Answer:
(a) A 95% confidence interval estimate of the percentage of orders that are not accurate is [0.125, 0.201].
(b) We can conclude that both restaurants can have the same inaccuracy rate due to the overlap of interval areas.
Step-by-step explanation:
We are given that in a study of the accuracy of fast food drive-through orders, Restaurant A had 302 accurate orders and 59 orders that were not accurate.
Firstly, the pivotal quantity for finding the confidence interval for the population proportion is given by;
P.Q. = [tex]\frac{\hat p-p}{\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] ~ N(0,1)
where, [tex]\hat p[/tex] = sample proportion of orders that were not accurate = [tex]\frac{59}{361}[/tex] = 0.163
n = sample of total orders = 302 + 59 = 361
p = population proportion of orders that are not accurate
Here for constructing a 95% confidence interval we have used a One-sample z-test for proportions.
So, 95% confidence interval for the population proportion, p is ;
P(-1.96 < N(0,1) < 1.96) = 0.95 {As the critical value of z at 2.5% level
of significance are -1.96 & 1.96}
P(-1.96 < [tex]\frac{\hat p-p}{\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] < 1.96) = 0.95
P( [tex]-1.96 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] < [tex]{\hat p-p}[/tex] < [tex]1.96 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] ) = 0.95
P( [tex]\hat p-1.96 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] < p < [tex]\hat p+1.96 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] ) = 0.95
95% confidence interval for p = [ [tex]\hat p-1.96 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] , [tex]\hat p+1.96 \times {\sqrt{\frac{\hat p(1-\hat p)}{n} } }[/tex] ]
= [ [tex]0.163 -1.96 \times {\sqrt{\frac{0.163(1-0.163)}{361} } }[/tex] , [tex]0.163 +1.96 \times {\sqrt{\frac{0.163(1-0.163)}{361} } }[/tex] ]
= [0.125, 0.201]
(a) Therefore, a 95% confidence interval estimate of the percentage of orders that are not accurate is [0.125, 0.201].
(b) We are given that the 95% confidence interval for the percentage of orders that are not accurate at Restaurant B is [0.143 < p < 0.219].
Here we can observe that there is a common area of inaccurate order of 0.058 or 5.85% for both the restaurants.
So, we can conclude that both restaurants can have the same inaccuracy rate due to the overlap of interval areas.
let x = the amoun of raw sugar in tons a procesing plant is a sugar refinery process in one day . suppose x can be model as exponetial distribution with mean of 4 ton per day . The amount of raw sugar (x) has
Answer:
The answer is below
Step-by-step explanation:
A sugar refinery has three processing plants, all receiving raw sugar in bulk. The amount of raw sugar (in tons) that one plant can process in one day can be modelled using an exponential distribution with mean of 4 tons for each of three plants. If each plant operates independently,a.Find the probability that any given plant processes more than 5 tons of raw sugar on a given day.b.Find the probability that exactly two of the three plants process more than 5 tons of raw sugar on a given day.c.How much raw sugar should be stocked for the plant each day so that the chance of running out of the raw sugar is only 0.05?
Answer: The mean (μ) of the plants is 4 tons. The probability density function of an exponential distribution is given by:
[tex]f(x)=\lambda e^{-\lambda x}\\But\ \lambda= 1/\mu=1/4 = 0.25\\Therefore:\\f(x)=0.25e^{-0.25x}\\[/tex]
a) P(x > 5) = [tex]\int\limits^\infty_5 {f(x)} \, dx =\int\limits^\infty_5 {0.25e^{-0.25x}} \, dx =-e^{-0.25x}|^\infty_5=e^{-1.25}=0.2865[/tex]
b) Probability that exactly two of the three plants process more than 5 tons of raw sugar on a given day can be solved when considered as a binomial.
That is P(2 of the three plant use more than five tons) = C(3,2) × [P(x > 5)]² × (1-P(x > 5)) = 3(0.2865²)(1-0.2865) = 0.1757
c) Let b be the amount of raw sugar should be stocked for the plant each day.
P(x > a) = [tex]\int\limits^\infty_a {f(x)} \, dx =\int\limits^\infty_a {0.25e^{-0.25x}} \, dx =-e^{-0.25x}|^\infty_a=e^{-0.25a}[/tex]
But P(x > a) = 0.05
Therefore:
[tex]e^{-0.25a}=0.05\\ln[e^{-0.25a}]=ln(0.05)\\-0.25a=-2.9957\\a=11.98[/tex]
a ≅ 12
In 2015, the CDC analyzed whether American adults were eating enough fruits and vegetables. Let the mean cups of vegetables adults eat in a day be μ. If the CDC wanted to know if adults were eating, on average, more than the recommended 2 cups of vegetables a day, what are the null and alternative hypothesis? Select the correct answer below: H0: μ=2; Ha: μ>2 H0: μ>2; Ha: μ=2 H0: μ=2; Ha: μ<2 H0: μ=2; Ha: μ≠2
Answer:
H0: μ=2; Ha: μ>2
Step-by-step explanation:
The null hypothesis is the default hypothesis while the alternative hypothesis is the opposite of the null and is always tested against the null hypothesis.
In this case study, the null hypothesis is that adults were eating, on average, the recommended 2 cups of vegetables a day: H0: μ=2 while the alternative hypothesis is adults were eating, on average, more than the recommended 2 cups of vegetables a day Ha: μ>2.
What is the range of the function F(x) graphed below?F(x)= -(x+2)^2+3
Answer:
range of the function F(x) is (-infinity, 3)
Step-by-step explanation:
I do not see the graph function F(x), so will assume that it is a graph of the function F(x) over the complete domain (-inf,inf).
As you can see from the attached graph, the function reaches a maximum at y=+3, and extends all the way to -infinity.
So the range of the function F(x) is (-infinity, 3)
need answers (ASAP!!!) with equations, please!!
Answer:
a=6, b=5.5
Step-by-step explanation:
By looking at the sides of the triangles it can easily be seen that some of the sides match up. Side b is similar to the side of 11 and same with side a and the side of 3. Since one side is 16 and the other side on the smaller triangle is 8, the bigger triangle is twice as large than the smaller one. So 3 x 2 = 6 and 11 / 2 = 5.5
please help all i need is the slope in case the points are hard to see here they are problem 1. (-2,2) (3,-3) problem 2. (-5,1) (4,-2) problem 3. (-1,5) (2,-4)
Answer: 1. [tex]-\dfrac{5}{6}[/tex] 2. [tex]-\dfrac{1}{3}[/tex] . 3. [tex]-3[/tex]
Step-by-step explanation:
Formula: Slope[tex]=\dfrac{y_2-y_1}{x_2-x_1}[/tex]
1. (-2,2) (3,-3)
Slope [tex]=\dfrac{-3-2}{3-(-2)}[/tex]
[tex]=\dfrac{-5}{3+2}\\\\=\dfrac{-5}{6}[/tex]
Hence, slope of line passing through (-2,2) (3,-3) is [tex]-\dfrac{5}{6}[/tex] .
2. (-5,1) (4,-2)
Slope [tex]=\dfrac{-2-1}{4-(-5)}[/tex]
[tex]=\dfrac{-3}{4+5}\\\\=\dfrac{-3}{9}\\\\=-\dfrac{1}{3}[/tex]
Hence, slope of line passing through (-2,2) and (3,-3) is [tex]-\dfrac{1}{3}[/tex] .
3. (-1,5) (2,-4)
Slope [tex]=\dfrac{-4-5}{2-(-1)}[/tex]
[tex]=\dfrac{-9}{2+1}\\\\=\dfrac{-9}{3}\\\\=-3[/tex]
Hence, slope of line passing through (-1,5) and (2,-4) is -3.
A regression model between sales (y in $1000), unit price (x1 in dollars), and television advertisement (x2 in dollars) resulted in the following function: Ŷ = 7 - 3x1 + 5x2 For this model, SSR = 3500, SSE = 1500, and the sample size is 18. If we want to test for the significance of the regression model, the critical value of F at the 5% level of significance is a. 3.29. b. 3.24. c. 3.68. d. 4.54.
Answer: C. 3.68
Step-by-step explanation:
Given that;
Sample size n = 18
degree of freedom for numerator k = 2
degree of freedom for denominator = n - k - 1 = (18-2-1) = 15
level of significance = 5% = 5/100 = 0.05
From the table values,
the critical value of F at 0.05 significance level with (2, 18) degrees of freedom is 3.68
Therefore option C. 3.68 is the correct answer
A car travels 133 mi averaging a certain speed. If the car had gone 30 mph faster, the trip would have taken 1 hr less. Find the car's average speed.
Answer:
49.923 mph
Step-by-step explanation:
we know that the car traveled 133 miles in h hours at an average speed of x mph.
That is, xh = 133.
We can also write this in terms of hours driven: h = 133/x.
If x was 30 mph faster, then h would be one hour less.
That is, (x + 30)(h - 1) = 133, or h - 1 = 133/(x + 30).
We can rewrite the latter equation as h = 133/(x + 30) + 1
We can then make a system of equations using the formulas in terms of h to find x:
h = 133/x = 133/(x + 30) + 1
133/x = 133/(x + 30) + (x + 30)/(x + 30)
133/x = (133 + x + 30)/(x + 30)
133 = x*(133 + x + 30)/(x + 30)
133*(x + 30) = x*(133 + x + 30)
133x + 3990 = 133x + x^2 + 30x
3990 = x^2 + 30x
x^2 + 30x - 3990 = 0
Using the quadratic formula:
x = [-b ± √(b^2 - 4ac)]/2a
= [-30 ± √(30^2 - 4*1*(-3990))]/2(1)
= [-30 ± √(900 + 15,960)]/2
= [-30 ± √(16,860)]/2
= [-30 ± 129.846]/2
= 99.846/2 ----------- x is miles per hour, and a negative value of x is neglected, so we'll use the positive value only)
= 49.923
Check if the answer is correct:
h = 133/49.923 = 2.664, so the car took 2.664 hours to drive 133 miles at an average speed of 49.923 mph.
If the car went 30 mph faster on average, then h = 133/(49.923 + 30) = 133/79.923 = 1.664, and 2.664 - 1 = 1.664.
Thus, we have confirmed that a car driving 133 miles at about 49.923 mph would have arrive precisely one hour earlier by going 30 mph faster
A triangle has interior measures of 32° and 90°. What is the measure of the third angle?
Answer:
58°Step-by-step explanation:
Let the measure of third angle be X
The sum of interior angle of triangle = X
Let's create an equation
[tex]x + 32 + 90 = 180[/tex]
Add the numbers
[tex]x + 122 = 180[/tex]
Move constant to R.H.S and change its sign
[tex]x = 180 - 122[/tex]
Subtract the numbers
[tex]x = 58[/tex] °
Hope this helps...
Best regards!!
the price of apples at three different stores is shown below. Store R sells apples for $1.20 per pound. Store S sells 4 pounds of apples for $5.00. Store T sells 3 pounds of apples for $3.48.
which of these is a true statemnt
Store R sells apples at the lowest rate
Store T sells apples at the lowest rate
Store s charges a lower rate than Store T
Store t charges the same rate as Store R
Store T sells apples at the lowest rate
Step-by-step explanation:
1st We need to make every statement in order of 1 pound. Then We will easily find the lowest rate of apple.
i) R sell 1.20 $ per pound.
ii) S sell 4 pounds for 5$
i.e S sell 1 pound for 5/4 = 1.25$
iii) T sell 3 pound for 3.48$
i.e T sell 1 pound for 3.48/3 = 1.16$
Analysing the above data I get,
Store T sells apples at the lowest rate
Assume that there is a 6% rate of disk drive failure in a year. a. If all your computer data is stored on a hard disk drive with a copy stored on a second hard disk drive, what is the probability that during a year, you can avoid catastrophe with at least one working drive? b. If copies of all your computer data are stored on independent hard disk drives, what is the probability that during a year, you can avoid catastrophe with at least one working drive? four a. With two hard disk drives, the probability that catastrophe can be avoided is . (Round to four decimal places as needed.) b. With four hard disk drives, the probability that catastrophe can be avoided is . (Round to six decimal places as needed.)
Answer: 0.9964
Step-by-step explanation:
Consider,
P (disk failure) = 0.06
q = 0.06
p = 1- q
p = 1- 0.06,
p = 0.94
Step 2
Whereas p represents the probability that a disk does not fail. (i.e. working entire year).
a)
Step 3
a)
n = 2,
let x be a random variable for number...
Continuation in the attached document
Solve : 1 − | 0.2(m−3)+ 1/4| =0
Answer:
1-{0.2(m-3)+¼}=0
1{0.2m-0.6+¼}=0
1-{(0.8m-2.4+1)/4}=0
1-(0.8m-1.4)/4=0
lcm
(4-0.8m-1.4)/4=0
(2.6-0.8m)/4=0
cross multiply
2.6-0.8m=0
m=2.6/0.8
m=3.25
The solution of the expression are,
⇒ m = 3.25
What is an expression?Mathematical expression is defined as the collection of the numbers variables and functions by using operations like addition, subtraction, multiplication, and division.
Given that;
Expression is,
⇒ 1 - | 0.2 (m - 3) + 1/4 | = 0
Now, We can simplify as;
⇒ 1 - | 0.2m - 0.6 + 1/4| = 0
⇒ 1 - |0.2m - 0.6 + 0.25| = 0
⇒ 1 - |0.2m - 0.35| = 0
⇒ 1 = 0.2m + 0.35
⇒ 1 - 0.35 = 0.2m
⇒ 0.2m = 0.65
⇒ m = 3.25
Thus, The solution of the expression are,
⇒ m = 3.25
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17. An electrical firm manufactures light bulbs that have a length of life that is approximately normally distributed with a standard deviation of 40 hours. How large a sample is need it if we wish to be 98% confident that our sample mean will be within 4 hours of the true mean
Answer:
A sample of at least 541 is needed if we wish to be 98% confident that our sample mean will be within 4 hours of the true mean.
Step-by-step explanation:
We are given that an electrical firm manufactures light bulbs that have a length of life that is approximately normally distributed with a standard deviation of 40 hours.
We have to find a sample such that we are 98% confident that our sample mean will be within 4 hours of the true mean.
As we know that the Margin of error formula is given by;
The margin of error = [tex]Z_(_\frac{\alpha}{2}_) \times \frac{\sigma}{\sqrt{n} }[/tex]
where, [tex]\sigma[/tex] = standard deviation = 40 hours
n = sample size
[tex]\alpha[/tex] = level of significance = 1 - 0.98 = 0.02 or 2%
Now, the critical value of z at ([tex]\frac{0.02}{2}[/tex] = 1%) level of significance n the z table is given as 2.3263.
So, the margin of error = [tex]Z_(_\frac{\alpha}{2}_) \times \frac{\sigma}{\sqrt{n} }[/tex]
[tex]4=2.3263 \times \frac{40}{\sqrt{n} }[/tex]
[tex]\sqrt{n}= \frac{40 \times 2.3263}{ 4}[/tex]
[tex]\sqrt{n}=23.26[/tex]
n = [tex]23.26^{2}[/tex] = 541.03 ≈ 541
Hence, a sample of at least 541 is needed if we wish to be 98% confident that our sample mean will be within 4 hours of the true mean.
Which of the following is false? Correlation measures the strength of linear association between two numerical variables. If the correlation between two variables is close to 0.01, then there is a very weak linear relation between them. Correlation coefficient and the slope always have the same sign (positive or negative). If the correlation coefficient is 1, then the slope must be 1 as well.
Answer:
If the correlation coefficient is 1, then the slope must be 1 as well.
Step-by-step explanation:
Coefficient of correlation is used in statistics to determine the relationship between two variables. Correlation coefficient and slope always have same sign. It measures the strength of linear relation between two variables. The values of correlation coefficient ranges between 0 to 1. where 0 determines that there is no relationship between two variables.
Please help asap.
A pizza is cut into six unequal slices (each cut starts at the center). The largest slice measures $90$ degrees If Larry eats the slices in order from the largest to the smallest, then the number of degrees spanned by a slice decreases at a constant rate. (So the second slice is smaller than the first by a certain number of degrees, then the third slice is smaller than the second slice by that same number of degrees, and so on.) What is the degree measure of the fifth slice Larry eats?
Answer:
The answer is 5th angle = [tex]\bold{42^\circ}[/tex]
Step-by-step explanation:
Given that pizza is divided into six unequal slices.
Largest slice has an angle of [tex]90^\circ[/tex].
He eats the pizza from largest to smallest.
Let the difference in angles in each slice = [tex]d^\circ[/tex]
1st angle = [tex]90^\circ[/tex]
2nd angle = 90-d
3rd angle = 90-d-d = 90 - 2d
4th angle = 90-2d-d = 90 - 3d
5th angle = 90-3d-d = 90 - 4d
6th angle = 90-4d -d = 90 - 5d
We know that the sum of all the angles will be equal to [tex]360^\circ[/tex] (The sum of all the angles subtended at the center).
i.e.
[tex]90+90-d+90-2d+90-3d+90-4d+90-5d=360\\\Rightarrow 540 - 15d = 360\\\Rightarrow 15d = 540 -360\\\Rightarrow 15d = 180\\\Rightarrow d = 12^\circ[/tex]
So, the angles will be:
1st angle = [tex]90^\circ[/tex]
2nd angle = 90- 12 = 78
3rd angle = 78-12 = 66
4th angle = 66-12 = 54
5th angle = 54-12 = 42
6th angle = 42 -12 = 30
So, the answer is 5th angle = [tex]\bold{42^\circ}[/tex]
Sam weights 51kg. What is this weight to the nearest stone?. Use this conversion, 1kg= 2.2 pounds and 14 pounds= 1 stone
Sam's weight to the nearest stone is equal to 8.0 stone.
Given the following data:
Sam's weight = 51 kg.1 kg = 2.2 pounds.14 pounds = 1 stone.To determine Sam's weight to the nearest stone:
How to convert the units of measurement.In this exercise, you're required to determine Sam's weight to the nearest stone. Thus, we would convert his weight in kilograms to pounds and lastly to stone as follows:
Conversion:
1 kg = 2.2 pounds.
51 kg = [tex]51 \times 2.2[/tex] = 112.2 pounds.
Next, we would convert the value in pounds to stone:
14 pounds = 1 stone.
112.2 pounds = X stone.
Cross-multiplying, we have:
[tex]14X = 112.2\\\\X=\frac{112.2}{14}[/tex]
X = 8.01 ≈ 8.0 stone.
Read more on weight here: brainly.com/question/13833323
may someone assist me?
Answer:
28
Step-by-step explanation:
Let x be the missing segment
We will use the proportionality property to find x
24/16 = 42/x
Simplify 24/16
24/16= (4×6)/(4×4)= 4/6 = 3/2
So 3/2 = 42/x
3x = 42×2
3x = 84
x = 84/3
x= 28
In which table does y vary inversely with x? A. x y 1 3 2 9 3 27 B. x y 1 -5 2 5 3 15 C. x y 1 18 2 9 3 6 D. x y 1 4 2 8 3 12
Answer:
In Table C, y vary inversely with x.
1×18 = 18
2×9 = 18
3×6 = 18
18 = 18 = 18
Step-by-step explanation:
We are given four tables and asked to find out in which table y vary inversely with x.
We know that an inverse relation has a form given by
y = k/x
xy = k
where k must be a constant
Table A:
x | y
1 | 3
2 | 9
3 | 27
1×3 = 3
2×9 = 18
3×27 = 81
3 ≠ 18 ≠ 81
Hence y does not vary inversely with x.
Table B:
x | y
1 | -5
2 | 5
3 | 15
1×-5 = -5
2×5 = 10
3×15 = 45
-5 ≠ 10 ≠ 45
Hence y does not vary inversely with x.
Table C:
x | y
1 | 18
2 | 9
3 | 6
1×18 = 18
2×9 = 18
3×6 = 18
18 = 18 = 18
Hence y vary inversely with x.
Table D:
x | y
1 | 4
2 | 8
3 | 12
1×4 = 4
2×8 = 16
3×12 = 36
4 ≠ 16 ≠ 36
Hence y does not vary inversely with x.
the value of 4^-1+8^-1÷1/2/3^3
Answer:
1.9375.
Step-by-step explanation:
To solve this, we must use PEMDAS.
The first things we take care of are parentheses and exponents.
Since there are no parentheses, we do exponents.
4^-1+8^-1÷1/2/3^3
= [tex]\frac{1}{4} +\frac{1}{8} / 1/ 2/ 27[/tex]
= 1/4 + (1/8) / 1 * (27 / 2)
= 1/4 + (27 / 8) / 2
= 1/4 + (27 / 8) * (1 / 2)
= 1/4 + (27 / 16)
= 4 / 16 + 27 / 16
= 31 / 16
= 1.9375.
Hope this helps!
In the search to determine if car 1 is slower to accelerate than car 2, the mean time it takes to accelerate to 30 miles per hour is recorded (Note: a car is slower to accelerate if it takes more time to accelerate). Twenty trials of the acceleration time for each car are recorded, and both populations have normal distributions with known standard deviations. What are the hypotheses used in this test
Answer:
Step-by-step explanation:
The happiest used in a test in statistics are the null and the alternative hypothesis. The null hypothesis is usually the default statement while the alternative hypothesis is thevopposite of the null hypothesis.
In this case study, the null hypothesis is u1 = u2: the average mean time it takes to accelerate to 30 miles per hour for car 1 is the same as that for car 2.
The alternative hypothesis is u1 > u2: the mean time it takes to accelerate to 30 miles per hour is greater than that for car 2 thus car 1 is slower to accelerate as it takes more time.
An angle measures 125.6° less than the measure of its supplementary angle. What is the measure of each angle?
Answer:
The measure of each angle:
152.8° and 27.2°
Step-by-step explanation:
Supplementary angles sum 180°
then:
a + b = 180°
a - b = 125.6°
then:
a = 180 - b
a = 125.6 + b
180 - b = 125.6 + b
180 - 125.6 = b + b
54.4 = 2b
b = 54.4/2
b = 27.2°
a = 180 - b
a = 180 - 27.2
a = 152.8°
Check:
152.8 + 27.2 = 180°
Answers:
152.8° & 27.2°Step-by-step explanation:
Let x and y be the measures of each angle.
x + y = 180°
x - y = 125.6°
180 - 125.6 = 54.4
Now we divide 54.4 evenly to get y.
y = 27.2°
To get x, we substitute y into the equation.
x = 27.2 + 125.6
x = 152.8°
To check, we plug these in to see if they equal 180°.
27.2 + 152.8 = 180° ✅
I'm always happy to help :)Which statement about the following equation is true?
2x2-9x+2-1
Complete Question:
Which statement about the following equation is true?
[tex]2x^2-9x+2 = -1[/tex]
A) The discriminant is less than 0, so there are two real roots
B) The discriminant is less than 0, so there are two complex roots
C) The discriminant is greater than 0, so there are two real roots
D) The discriminant is greater than 0, so there are two complex roots
Answer:
C) The discriminant is greater than 0, so there are two real roots
Step-by-step explanation:
The given equation is [tex]2x^2-9x+2 = -1[/tex] which by simplification becomes
[tex]2x^2 - 9x + 3 = 0[/tex]
For a quadratic equation of the form [tex]ax^2 + bx + c = 0[/tex], the discriminant is given by the equation, [tex]D = b^2 - 4ac[/tex]
If the discriminant D is greater than 0, the roots are real and different
If the discriminant D is equal to 0, the roots are real and equal
If the discriminant D is less than 0, the roots are imaginary
For the quadratic equation under consideration, a = 2, b = -9, c = 3
Let us calculate the discriminant D
D = (-9)² - 4(2)(3)
D = 81 - 24
D = 57
Since the Discriminant D is greater than 0, the roots are real and different.
Answer:
Step-by-step explanation:
C) The discriminant is greater than 0, so there are two real roots
Find the directional derivative of f at the given point in the direction indicated by the angle θ. f(x, y) = y cos(xy), (0, 1), θ = π/3
Answer:
√3/2
Explanation:
The directional derivative at the given point is gotten using the formula;
∇f(x,y)•u where u is the unit vector in that direction.
∇f(x,y) = f/x i + f/y j
Given the function f(x, y) = y cos(xy),
f/x = -y²sin(xy) and
f/y = -xysin(xy)+cos(xy)
∇f(x,y) = -y²sin(xy) i + (cos(xy)-xysin(xy)) j
∇f(x,y) at (0,1) will give;
∇f(0,1) = -0sin0 i + cos0j
∇f(0,1) = 0i+j
The unit vector in the direction of angle θ is given as u = cosθ i + sinθ j
u = cos(π/3)i+ sin(π/3)j
u = 1/2 i + √3/2 j
Taking the dot product of both vectors;
∇f(x,y)•u = (0i+j)•(1/2 i + √3/2 j)
Note that i.i = j.j = 1 and i.j = 0
∇f(x,y)•u = 0 + √3/2
∇f(x,y)•u = √3/2
The directional derivative of [tex]f[/tex] at the given point in the direction indicated is [tex]\frac{\sqrt{3}}{2}[/tex].
How to calculate the directional derivative of a multivariate functionThe directional derivative is represented by the following formula:
[tex]\nabla_{\vec v} f = \nabla f(x_{o},y_{o}) \cdot \vec v[/tex] (1)
Where:
[tex]\nabla f(x_{o}, y_{o})[/tex] - Gradient evaluated at point [tex](x_{o},y_{o})[/tex].[tex]\vec v[/tex] - Directional vectorThe gradient of [tex]f[/tex] is calculated below:
[tex]\nabla f (x_{o},y_{o}) = \left[\begin{array}{cc}\frac{\partial f}{\partial x} (x_{o}, y_{o}) \\\frac{\partial f}{\partial y} (x_{o}, y_{o})\end{array}\right][/tex] (2)
Where [tex]\frac{\partial f}{\partial x}[/tex] and [tex]\frac{\partial f}{\partial y}[/tex] are the partial derivatives with respect to [tex]x[/tex] and [tex]y[/tex], respectively.
If we know that [tex](x_{o}, y_{o}) = (0, 1)[/tex], then the gradient is:
[tex]\nabla f(x_{o}, y_{o}) = \left[\begin{array}{cc}-y^{2}\cdot \sin xy\\\cos xy -x\cdot y\cdot \sin xy\end{array}\right][/tex]
[tex]\nabla f (x_{o}, y_{o}) = \left[\begin{array}{cc}-1^{2}\cdot \sin 0\\\cos 0-0\cdot 1\cdot \sin 0\end{array}\right][/tex]
[tex]\nabla f (x_{o}, y_{o}) = \left[\begin{array}{cc}0\\1\end{array}\right][/tex]
If we know that [tex]\vec v = \cos \frac{\pi}{3}\,\hat{i} + \sin \frac{\pi}{3} \,\hat{j}[/tex], then the directional derivative is:
[tex]\Delta_{\vec v} f = \left[\begin{array}{cc}0\\1\end{array}\right]\cdot \left[\begin{array}{cc}\cos \frac{\pi}{3} \\\sin \frac{\pi}{3} \end{array}\right][/tex]
[tex]\nabla_{\vec v} f = (0)\cdot \cos \frac{\pi}{3} + (1)\cdot \sin \frac{\pi}{3}[/tex]
[tex]\nabla_{\vec v} f = \frac{\sqrt{3}}{2}[/tex]
The directional derivative of [tex]f[/tex] at the given point in the direction indicated is [tex]\frac{\sqrt{3}}{2}[/tex]. [tex]\blacksquare[/tex]
To learn more on directional derivatives, we kindly invite to check this verified question: https://brainly.com/question/9964491
Please help. I’ll mark you as brainliest if correct!
Answer:
8lb of the cheaper Candy
17.5lb of the expensive candy
Step-by-step explanation:
Let the cheaper candy be x
let the costly candy be y
X+y = 25.5....equation one
2.2x +7.3y = 25.5(5.7)
2.2x +7.3y = 145.35.....equation two
X+y = 25.5
2.2x +7.3y = 145.35
Solving simultaneously
X= 25.5-y
Substituting value of X into equation two
2.2(25.5-y) + 7.3y = 145.35
56.1 -2.2y +7.3y = 145.35
5.1y = 145.35-56.1
5.1y = 89.25
Y= 89.25/5.1
Y= 17.5
X= 25.5-y
X= 25.5-17.5
X= 8
What is the rate of change of the function
The average rate of change between two input values is the total change of the function values (output values) divided by the change in the input values.
Compute the following values when the log is defined by its principal value on the open set U equal to the plane with the positive real axis deleted.
a. log i
b. log(-1)
c. log(-1 + i)
d. i^i
e. (-i)^i
Answer:
Following are the answer to this question:
Step-by-step explanation:
The principle vale of Arg(3)
[tex]Arg(3)=-\pi+\tan^{-1} (\frac{|Y|}{|x|})[/tex]
The principle value of the [tex]\logi= \log(0+i)\ \ \ \ \ _{where} \ \ \ x=0 \ \ y=1> 0[/tex]
So, the principle value:
a)
[tex]\to \log(i)=\log |i|+i Arg(i)\\\\[/tex]
[tex]=\log \sqrt{0+1}+i \tan^{-1}(\frac{1}{0})\\\=\log 1 +i \tan^{-1}(\infty)\\\=0+i\frac{\pi}{2}\\\=i\frac{\pi}{2}[/tex]
b)
[tex]\to \log(-i)= \log(0-i ) \ \ \ x=0 \ \ \ y= -1<0\\[/tex]
Principle value:
[tex]\to \log(-i)= \log|-i|+iArg(-i) \\\\[/tex]
[tex]=\log \sqrt{0+1}+i(-\pi+\tan^{-1}(\infty))\\\\=\log1 + i(-\pi+\frac{\pi}{2})\\\\=-i\frac{\pi}{2}[/tex]
c)
[tex]\to \log(-1+i) \ \ \ \ x=-1, _{and} y=1 \ \ \ x<0 and y>0[/tex]
The principle value:
[tex]\to \log(-1+i)=\log |-1+i| + i Arg(-1+i)[/tex]
[tex]=\log \sqrt{1+1}+i(\pi+\tan^{-1}(\frac{1}{1}))\\\\=\log \sqrt{2} + i(\pi-\tan^{-1}\frac{\pi}{4})\\\\=\log \sqrt{2} + i\tan^{-1}\frac{3\pi}{4}\\\\[/tex]
d)
[tex]\to i^i=w\\\\w=e^{i\log i}[/tex]
The principle value:
[tex]\to \log i=i\frac{\pi}{2}\\\\\to w=e^{i(i \frac{\pi}{2})}\\\\=e^{-\frac{\pi}{2}}[/tex]
e)
[tex]\to (-i)^i\\\to w=(-i)^i\\\\w=e^{i \log (-i)}[/tex]
In this we calculate the principle value from b:
so, the final value is [tex]e^{\frac{\pi}{2}}[/tex]
f)
[tex]\to -1^i\\\\\to w=e^{i log(-1)}\\\\\ principle \ value: \\\\\to \log(-1)= \log |-1|+iArg(-i)[/tex]
[tex]=\log \sqrt{1} + i(\pi-\tan^{-1}\frac{0}{-1})\\\\=\log \sqrt{1} + i(\pi-0)\\\\=\log \sqrt{1} + i\pi\\\\=0+i\pi\\=i\pi[/tex]
and the principle value of w is = [tex]e^{\pi}[/tex]
g)
[tex]\to -1^{-i}\\\\\to w=e^(-i \log (-1))\\\\[/tex]
from the point f the principle value is:
[tex]\to \log(-1)= i\pi\\\to w= e^{-i(i\pi)}\\\\\to w=e^{\pi}[/tex]
h)
[tex]\to \log(-1-i)\\\\\ Here x=-1 ,<0 \ \ y=-1<0\\\\ \ principle \ value \ is:\\\\ \to \log(-1-i)=\log\sqrt{1+1}+i(-\pi+\tan^{-1}(1))[/tex]
[tex]=\log\sqrt{2}+i(-\pi+\frac{\pi}{4})\\\\=\log\sqrt{2}+i(-\frac{3\pi}{4})\\\\=\log\sqrt{2}-i\frac{3\pi}{4})\\[/tex]
a 12- inch ruler is duvided into 3 parts. the large part is 3 times longer than the small. the meddium part is times longer than then small, the medium part is 2 times long as the smallest .how long is the smallest part?
Answer:
2 inches
Step-by-step explanation:
x= smallest
3x=largest
2x=medium
x+3x+2x=12
6x=12
x=2
so smallest is 2
largest is 6 (3x)
medium is 4 (2x)
2+6+4=12
A subcommittee is randomly selected from a committee of eight men and seven women. What is the probability that all three people on the subcommittee are men
Answer:
The probability that all three people on the subcommittee are men
= 20%
Step-by-step explanation:
Number of members in the committee = 15
= 8 men + 7 women
The probability of selecting a man in the committee
= 8/15
= 53%
The probability of selecting three men from eight men
= 3/8
= 37.5%
The probability that all three people on the subcommittee are men
= probability of selecting a man multiplied by the probability of selecting three men from eight men
= 53% x 37.5%
= 19.875%
= 20% approx.
This is the same as:
The probability of selecting 3 men from the 15 member-committee
= 3/15
= 20%
Historically, the proportion of students entering a university who finished in 4 years or less was 63%. To test whether this proportion has decreased, 114 students were examined and 51% had finished in 4 years or less. To determine whether the proportion of students who finish in 4 year or less has statistically significantly decreased (at the 5% level of signficance), what is the critical value
Answer:
z(c) = - 1,64
We reject the null hypothesis
Step-by-step explanation:
We need to solve a proportion test ( one tail-test ) left test
Normal distribution
p₀ = 63 %
proportion size p = 51 %
sample size n = 114
At 5% level of significance α = 0,05, and with this value we find in z- table z score of z(c) = 1,64 ( critical value )
Test of proportion:
H₀ Null Hypothesis p = p₀
Hₐ Alternate Hypothesis p < p₀
We now compute z(s) as:
z(s) = ( p - p₀ ) / √ p₀q₀/n
z(s) =( 0,51 - 0,63) / √0,63*0,37/114
z(s) = - 0,12 / 0,045
z(s) = - 2,66
We compare z(s) and z(c)
z(s) < z(c) - 2,66 < -1,64
Therefore as z(s) < z(c) z(s) is in the rejection zone we reject the null hypothesis
Find the common ratio of the following geometric sequence:
11,55, 275, 1375, ....
Answer:
Hey there!
The common ratio is 5, because you multiply by 5 to get from one term to the next.
Hope this helps :)
Answer:
5
Step-by-step explanation:
To find the common ratio take the second term and divide by the first term
55/11 = 5
The common ratio would be 5
Which of the following is best described as sets of three whole numbers (a, b, and c) that satisfy the equation ?
A.
The Pythagorean theorem
B.
Prime numbers
C.
Pythagorean triples
D.
Perfect squares
Answer:
Option C
Step-by-step explanation:
The whole numbers a,b and c such that [tex]a^2+b^2 = c^2[/tex] are Pythagorean triples satisfying the Pythagorean theorem.
Answer:
C
Step-by-step explanation:
a, b, and c are side lengths of the triangle.
The three side lengths that make up a right triangle are most commonly known as Pythagorean triples.