Answer:
The statistic would be given by:
[tex]z=\frac{\hat p -p_o}{\sqrt{\frac{p_o (1-p_o)}{n}}}[/tex] (1)
And replacing we got:
[tex]z=\frac{0.65 -0.5}{\sqrt{\frac{0.5(1-0.5)}{421}}}=6.16[/tex]
Step-by-step explanation:
Information given
n=421 represent the random sample taken
[tex]\hat p=0.65[/tex] estimated proportion of adults that would erase all of their personal information online if they could
[tex]p_o=0.5[/tex] is the value that we want to test
z would represent the statistic
Hypothesis to test
We want to check if Most adults would erase all of their personal information online if they could, then the system of hypothesis are :
Null hypothesis:[tex]p\leq 0.5[/tex]
Alternative hypothesis:[tex]p > 0.5[/tex]
The statistic would be given by:
[tex]z=\frac{\hat p -p_o}{\sqrt{\frac{p_o (1-p_o)}{n}}}[/tex] (1)
And replacing we got:
[tex]z=\frac{0.65 -0.5}{\sqrt{\frac{0.5(1-0.5)}{421}}}=6.16[/tex]
From the information given, it is found that the value of the test statistic is z = 6.16.
At the null hypothesis, we test if it is not most adults that would erase all of their personal information online if they could, that is, the proportion is of at most 50%, hence:
[tex]H_0: p = 0.5[/tex]
At the alternative hypothesis, we test if most adults would, that is, if the proportion is greater than 50%.
[tex]H_1: p > 0.5[/tex]
The test statistic is given by:
[tex]z = \frac{\overline{p} - p}{\sqrt{\frac{p(1-p)}{n}}}[/tex]
In which:
[tex]\overline{p}[/tex] is the sample proportion. p is the proportion tested at the null hypothesis. n is the sample size.In this problem, the parameters are: [tex]p = 0.5, n = 421, \overline{p} = 0.65[/tex].
Hence, the value of the test statistic is:
[tex]z = \frac{\overline{p} - p}{\sqrt{\frac{p(1-p)}{n}}}[/tex]
[tex]z = \frac{0.65 - 0.5}{\sqrt{\frac{0.5(0.5)}{421}}}[/tex]
[tex]z = 6.16[/tex]
A similar problem is given at https://brainly.com/question/15908206
4 builders are building some new classrooms at Trinity. It takes them 5 months to build the classrooms. How long will it take 10 builders?
Answer:
it takes
[tex]\boxed {\red {2 \: \: months}}[/tex]
for 10 builders
Step-by-step explanation:
[tex]4 \: \: \: builders = 5 \: month \\ 10 \: builders = x[/tex]
Let us solve
[tex]4 = 5 \\ 10 = x[/tex]
so
[tex]4 = x \\ 10 = 5[/tex]
use cross multiplication
[tex]5 \times 4 = 10 \times x \\ 20 = 10x \\ \frac{20}{10} = \frac{10x}{10} \\ \green {x = 2}[/tex]
Answer:
[tex]\boxed{2months}[/tex]
Step-by-step explanation:
B1 = 4
M1 = 5
B2 = 10
M2 = x (we have to find this)
Since it is an inverse proportion (more builders will take less time and vive versa), we'll write it in the order of
=> B1 : B2 = M2 : M1
=> 4:10 = x : 5
Product of Means = Product of Extremes
=> 10*x = 4*5
=> 10x = 20
Dividing both sides by 10
=> x = 2 months
So, it will take 2 months to build classrooms by 10 builders.
Solve for x.
Simplify your answer as much as possible.
A rectangular prism made of wood has a length of 10 centimeters, a width of 8 centimeters, and a height of 12 centimeters. A rectangular hole
with a length of 2 centimeters and a width of 3 centimeters is cut through the prism as shown. What is the volume of the resulting figure?
3 cm
2 cm
12 cm
8 cm
10 cm
Answer: its B 888 cm
Step-by-step explanation: hope this helps let me know if wrong ill fix it
Which statement describes the system of equations?
X+ 2y = 2
x-2y=-2
It has infinitely many solutions.
It has no solution.
It has one solution (0, 1).
It has one solution (4, -1).
Answer:
It has one solution (0, 1).
Step-by-step explanation:
Easiest and fastest way to solve the systems of equation is to graph them on a graphing calc and analyzing where the 2 graphs intersect (if they are not parallel).
(1 point) A random sample of 1600 home owners in a particular city found 736 home owners who had a swimming pool in their backyard. Find a 95% confidence interval for the true percent of home owners in this city who have a swimming pool in their backyard. Express your results to the nearest hundredth of a percent.
Answer:
Answer: (0.4356,0.4844)
Step-by-step explanation:
Use Ti 84
use function "1-PropZInt".
Enter x = 736
n = 1600
c= 0.95
Answer: (0.4356,0.4844)
what is the difference of rational expressions below 6x/x-3 - 5/x
Answer:
[tex]$ \frac{6x^2-5x+15 }{x^2-3x} $[/tex]
Step-by-step explanation:
[tex]$\frac{6x}{x-3} -\frac{5}{x} $[/tex]
[tex]$\frac{6x(x)}{x(x-3)} -\frac{5(x-3)}{x(x-3)} $[/tex]
[tex]$\frac{6x^2}{x^2-3x} -\frac{5x-15}{x^2-3x} $[/tex]
[tex]$ \frac{6x^2-5x+15 }{x^2-3x} $[/tex]
QUESTION 2
Find Percent Increase:
The original price for a product is $53.93 and the sale's tax rate is 29%. Find the amount of tax and the total selling price. Round to the nearest cent.
A $15.64 and $69.57
B. $38.29 and 592.22
C. $15.64 and $38.29
D. $16.78 and $70.21
QUESTION 3
Find Future Value Using Simple Interest Formula:
Chad got a student loan for $10,000 at 8% annual simple interest. How much does he owe after two years?
A $12,800
B. $10,800
C. $11,600
D. $11,664
Answer:
QUESTION 2 -> Correct option: A.
QUESTION 3 -> Correct option: C.
Step-by-step explanation:
QUESTION 2
To find the amount of tax we just need to multiply the tax rate by the original price of the product:
[tex]Tax = 29\% * 53.93[/tex]
[tex]Tax = 0.29 * 53.93[/tex]
[tex]Tax =\$15.64[/tex]
Then, to find the total selling price, we need to sum the original price to the tax value:
[tex]Total = tax + price[/tex]
[tex]Total = 15.64 + 53.93[/tex]
[tex]Total = \$69.57[/tex]
Correct option: A.
QUESTION 3
To find the final value after 2 years, we can use the formula:
[tex]P = Po * (1 + r*t)[/tex]
Where P is the final value, Po is the inicial value, r is the interest and t is the amount of time. Then, we have that:
[tex]P = 10000 * (1 + 0.08 * 2)[/tex]
[tex]P = \$11600[/tex]
Correct option: C.
2. A line passes through the point (0,4).
The gradient of this line is 2.
Write down the equation of this line
Answer:
[tex]\boxed{y = 2x+4}[/tex]
Step-by-step explanation:
Gradient = m = 2
Y-intercept = b = 4 (Because here x = 0 as in the point (0,4))
So, the equation becomes
=> [tex]y = mx+b[/tex]
=> [tex]y = 2x+4[/tex]
what is the axis of symmetry of f(x)=-3(x+2)^2+4
Answer:
line passes through the vertex
Step-by-step explanation:
f(x)=-3(x+2)^2+4
x=-2 it is the x of the vertex
US consumers are increasingly using debit cards as a substitute for cash and checks. From a sample of 100 consumers, the average amount annually spent on debit cards is $7,790. Assume that this average was based on a sample of 100 consumers and that the population standard deviation is $500.
A. At 99% confidence, what is the margin of error?
B. Construct the 99% confidence interval for the population mean amount spent annually on a debit card.
Answer:
A. Margin of error = 128.79
B. The 99% confidence interval for the population mean is (7661.21, 7918.79).
Step-by-step explanation:
We have to calculate a 99% confidence interval for the mean.
The population standard deviation is know and is σ=500.
The sample mean is M=7790.
The sample size is N=100.
As σ is known, the standard error of the mean (σM) is calculated as:
[tex]\sigma_M=\dfrac{\sigma}{\sqrt{N}}=\dfrac{500}{\sqrt{100}}=\dfrac{500}{10}=50[/tex]
The z-value for a 99% confidence interval is z=2.576.
The margin of error (MOE) can be calculated as:
[tex]MOE=z\cdot \sigma_M=2.576 \cdot 50=128.79[/tex]
Then, the lower and upper bounds of the confidence interval are:
[tex]LL=M-t \cdot s_M = 7790-128.79=7661.21\\\\UL=M+t \cdot s_M = 7790+128.79=7918.79[/tex]
The 99% confidence interval for the population mean is (7661.21, 7918.79).
Prove the identity cos x/1 - sin x = sec x + tan x
Answer:
Proved
Step-by-step explanation:
Given
Prove that
[tex]\frac{cos x}{1 - sin x} = sec x + tan x[/tex]
[tex]\frac{cos x}{1 - sin x}[/tex]
Multiply the numerator and denominator by 1 + sinx
[tex]\frac{cos x}{1 - sin x} * \frac{1 + sin x}{1 + sin x}[/tex]
Combine both fractions to form 1
[tex]\frac{cos x (1 + sin x)}{(1 - sin x)(1 + sin x)}[/tex]
Expand the denominator using difference of two squares;
[tex]i.e.\ (a - b)(a + b) = a^2 - b^2[/tex]
The expression becomes
[tex]\frac{cos x (1 + sin x)}{(1^2 - sin^2 x)}[/tex]
[tex]\frac{cos x (1 + sin x)}{(1 - sin^2 x)}[/tex]
From trigonometry; [tex]1 - sin^2x = cos^2x[/tex]
The expression becomes
[tex]\frac{cos x (1 + sin x)}{(cos^2 x)}[/tex]
Divide the numerator and the denominator by cos x
[tex]\frac{(1 + sin x)}{(cos x)}[/tex]
Split fraction
[tex]\frac{1}{cos x} + \frac{sin x}{cos x}[/tex]
From trigonometry; [tex]\frac{1}{cos x} = sec x \ and\ \frac{sin\ x}{cos\ x} = tan\ x[/tex]
So;
[tex]\frac{1}{cos x} + \frac{sin x}{cos x}[/tex] = [tex]sec x + tan x[/tex]
7.1 A player throws a fair die and simultaneously flips a fair coin. If the coin lands heads, then she wins twice, and if tails, then she wins one-half of the value that appears on the die. Determine her expected winnings.
Answer:
1.875
Step-by-step explanation:
To find the expected winnings, we need to find the probability of all cases possible, multiply each case by the value of the case, and sum all these products.
In the die, we have 6 possible values, each one with a probability of 1/6, and the value of each output is half the value in the die, so we have:
[tex]E_1 = \frac{1}{6}\frac{1}{2} + \frac{1}{6}\frac{2}{2} +\frac{1}{6}\frac{3}{2} +\frac{1}{6}\frac{4}{2} +\frac{1}{6}\frac{5}{2} +\frac{1}{6}\frac{6}{2}[/tex]
[tex]E_1 = \frac{1}{12}(1+2+3+4+5+6)[/tex]
[tex]E_1 = \frac{21}{12} = \frac{7}{4}[/tex]
Now, analyzing the coin, we have heads or tails, each one with 1/2 probability. The value of the heads is 2 wins, and the value of the tails is the expected value of the die we calculated above, so we have:
[tex]E_2 = \frac{1}{2}2 + \frac{1}{2}E_1[/tex]
[tex]E_2 = 1 + \frac{1}{2}\frac{7}{4}[/tex]
[tex]E_2 = 1 + \frac{7}{8}[/tex]
[tex]E_2 = \frac{15}{8} = 1.875[/tex]
The point (3, 6) is on the graph of y= 5f(2(x+3))-4 . Find the original point on the graph of y=f(x).
Answer:
(12, 2) is the original point on the graph of [tex]y=f(x)[/tex].
Step-by-step explanation:
Given:
[tex]y= 5f(2(x+3))-4[/tex] has a point (3, 6) on its graph.
To find:
Original point on graph [tex]y=f(x)[/tex] = ?.
Solution:
We are given that The point (3, 6) is on the graph of [tex]y= 5f(2(x+3))-4[/tex]
If we put x = 3 and y = 6 in [tex]y= 5f(2(x+3))-4[/tex], it will satisfy the equation.
Let us the put the values and observe:
[tex]6= 5f(2(3+3))-4\\\Rightarrow 6= 5f(2(6))-4\\\Rightarrow 6= 5f(12)-4\\\Rightarrow 6+4=5f(12)\\\Rightarrow 5f(12)= 6+4\\\Rightarrow 5f(12)= 10\\\Rightarrow f(12)= \dfrac{10}{5}\\\Rightarrow f(12)= 2\\OR\\\Rightarrow 2=f(12)[/tex]
Now, let us compare the above with the following:
[tex]y=f(x)[/tex]
we get y = 2 and x = 12
So, the original point on graph of [tex]y=f(x)[/tex] is (12, 2).
1 pizza costs £3.20 more than a bottle of coke. The total cost of the items is £19.40 for 3 pizzas and 1 bottle of coke How much does a pizza cost? How do you work this out please?
Answer:
Step-by-step explanation
p - the price of pizza
c- the price of a bottle of coke
p = c+3.2
3p + c=19.4
3* (c+3.2)+c=19.4
3*c+3*3.2+c=19.4
3c+c+9.6=19.4
4c+9.6=19.4
-9.6 -9.6
4c=9.8
:4. :4
c=2.45
p=2.45+3.2=5.65
verify : 3*5.65+2.45=16.95+2.45=19.40
What is the value of 45-0.023
The value is 44.977
Feel pleasure to help u
Answer:
44.977
Step-by-step explanation:
A bag contains 75 marbles:35 are blue and 25 of these blue marbles are swirled. The rest of them are red, and 30 of the red ones are swirled. The marbles that are not swirled are clear. What is the probability of drawing? (a) A blue marble (b) A blue swirled marble (c) A red clear marble.
Answer:
a) 35/75
b)25/75
c)10/75
Step-by-step explanation:
Sample annual salaries (in thousands of dollars) for employees at a company are listed. 51 53 48 62 34 34 51 53 48 30 62 51 46 (a) Find the sample mean and sample standard deviation. (b) Each employee in the sample is given a $5000 raise. Find the sample mean and sample standard deviation for the revised data set. (c) Each employee in the sample takes a pay cut of $2000 from their original salary. Find the sample mean and the sample standard deviation for the revised data set. (d) What can you conclude from the results of (a), (b), and (c)?
Answer:
Mean increase or decrease (same quantity) according to the quantity of the increment or reduction
As all elements were equally affected the standard deviation will remain the same
Step-by-step explanation:
For the original set of salaries: ( In thousands of $ )
51, 53, 48, 62, 34, 34, 51, 53, 48, 30, 62, 51, 46
Mean = μ₀ = 47,92
Standard deviation = σ = 9,56
If we raise all salaries in the same amount ( 5 000 $ ), the nw set becomes
56,58,53,67,39,39,56,58,53,35,67,56,51
Mean = μ₀´ = 52,92
Standard deviation = σ´ = 9,56
And if we reduce salaries in the same quantity ( 2000 $ ) the set is
49,51,46,60,32,32,49,51,46,28,60,49,44
Mean μ₀´´ = 45,92
Standard deviation σ´´ = 9,56
What we observe
1.-The uniform increase of salaries, increase the mean in the same amount
2.-The uniform reduction of salaries, reduce the mean in the same quantity
3.-The standard deviation in all the sets remains the same.
We can describe the situation as a translation of the set along x-axis (salaries). If we normalized the three curves we will get a taller curve (in the first case) and a smaller one in the second, but the data spread around the mean will be the same
Any uniform change in the data will directly affect the mean value
Uniform changes in values in data set will keep standard deviation constant
When five times a number is decreased by 8, the result is 7. What is the number?
The number is
Answer:
3
Step-by-step explanation:
5x - 8 = 7
5x = 7+8
5x = 15
x = 15 ÷ 5
x = 3
In the probability distribution to the right, the random variable X represents the number of marriages an individual aged 15 years or older has been involved in. Compute and interpret the mean of the random variable X.
The table of the probability is missing, so i have attached it.
Answer:
μ = 0.919
The interpretation of this is that;on the average, an individual aged 15 years or older has been involved in 0.919 marriages.
Step-by-step explanation:
The expected value which is also called mean value is denoted by the symbol μ. It is defined as the sum of the product of each possibility x with it's probability P(x) as the formula;
μ = Σx.P(x) = (0 × 0.272) + (1 × 0.575) + (2 × 0.121) + (3 × 0.027) + (4 × 0.004) + (5 × 0.001)
μ = 0.919
Thus, the interpretation of this is that;on the average, an individual aged 15 years or older has been involved in 0.919 marriages.
The interpretation of the mean of the random variable X is 0.919.
Calculation of the mean:
Here the interpretation should represent the average and it should be individual aged 15 years or more so it should be involved in 0.919 marriage.
Now the mean is
μ = Σx.P(x) = (0 × 0.272) + (1 × 0.575) + (2 × 0.121) + (3 × 0.027) + (4 × 0.004) + (5 × 0.001)
μ = 0.919
Hence, The interpretation of the mean of the random variable X is 0.919.
Learn more about mean here: https://brainly.com/question/20875379
Pamela is 7years older than jiri. The sum of their age is 91. What is Jori’s age
Answer:
[tex]\boxed{\sf \ \ \text{Jori is 42} \ \ }[/tex]
Step-by-step explanation:
Hello,
Let's not J Jori's age
Pamela is 7 years older than Jori so here age is J + 7
The sum of their age is 91 so
J + ( J + 7 ) = 91
<=>
2J + 7 = 91 subtract 7
2J = 91 - 7 = 84 divide by 2
J = 84/2 = 42
So Jori is 42 and Pamela is 49
hope this helps
Solve the system by graphing (Simplify your answer completely.)
Will someone please help me with this and give an explanation on how you got it? I don’t understand.
{x+y=8
{x-y=4
Answer:
(6,2)
Step-by-step explanation:
1) convert both equations to slope intercept form:
y=-x+8
and
y=x-4
now graph both equations separately by intercepts:
x int: 0=-x+8
-8=-x
8=x
y int: y=0+8
y=8
so the two coordinate points for first equation are (0,8) and (8,0)
lets move on two second equation: y=x-4
x int: 0=x-4
4=x
y int y=0-4
y=-4
so the 2 coordinate points are (4,0) and (0,4)
lets graph these two equations and see where they intersect:
(see graph below), the intersection is at (6,2) so (6,2) is our answer
hope this helps
A- y=-2x-4
B- y=2x+4
C- y=-2x+4
D- y= 2x-4
Answer:
A. y=-2x-4
Step-by-step explanation:
The slope is negative when the line is going down from up.
Options B and D are wrong.
The y-intercept is (0, -4) as shown in the graph.
Option C is wrong.
y = mx + b
y = -2x - 4
What are the divisors of 60?
Answer:
Step-by-step explanation:
The divisors of a number are the numbers that divide it exactly.
60/2
2/30
3/3
5/5
one
divisors = 1,2,3,, 4,5,6,10,12,15,20,30,60.
answer:
1, 2, 3, 6, 10, 30, 60
Step-by-step explanation:
i am pretty sure!
A random variable X counts the number of successes in 20 independent trials. The probability that any one trial is unsuccessful is 0.42. What is the probability of exactly eight successful trials
Answer:
[tex] P(X=8)[/tex]
And using the probability mass function we got:
[tex]P(X=8)=(20C8)(0.58)^8 (1-0.58)^{20-8}=0.0486[/tex]
Step-by-step explanation:
Let X the random variable of interest, on this case we now that:
[tex]X \sim Binom(n=20, p=1-0.42=0.58)[/tex]
The probability mass function for the Binomial distribution is given as:
[tex]P(X)=(nCx)(p)^x (1-p)^{n-x}[/tex]
Where (nCx) means combinatory and it's given by this formula:
[tex]nCx=\frac{n!}{(n-x)! x!}[/tex]
And we want to find this probability:
[tex] P(X=8)[/tex]
And using the probability mass function we got:
[tex]P(X=8)=(20C8)(0.58)^8 (1-0.58)^{20-8}=0.0486[/tex]
The probability of exactly eight successful trials is 0.0486 and this can be determined by using the formula of the probability mass function.
Given :
A random variable X counts the number of successes in 20 independent trials.The probability that any one trial is unsuccessful is 0.42.According to the binomial distribution, the probability mass function is given by:
[tex]\rm P(X) = \; (^nC_x )(p^x)(1-p)^{n-x}[/tex]
where the value of n is 20 and the value of (p = 1 - 0.42 = 0.58).
Now, substitute the values of known terms in the above expression of probability mass function.
[tex]\rm P(X=8) = \; (^{20}C_8 )((0.58)^8)(1-0.58)^{20-8}[/tex]
Simplify the above expression in order to determine the probability of exactly eight successful trials.
P(X = 8) = 0.0486
For more information, refer to the link given below:
https://brainly.com/question/23017717
Precalc experts! I need your help!
Answer:
[tex]f(x)\to 1[/tex]
Step-by-step explanation:
The function approaches its horizontal asymptote in both directions as the magnitude of x gets large. The limit is y = 1.
How many solutions does the system have? { y = − 3 x + 9 3 y = − 9 x + 9 ⎩ ⎪ ⎪ ⎨ ⎪ ⎪ ⎧ y=−3x+9 3y=−9x+9
Answer:
no solutions
Step-by-step explanation:
y = − 3 x + 9
3 y = − 9 x + 9
Multiply the first equation by -3
-3(y )=-3( − 3 x + 9)
-3y = 9x -27
3 y = − 9 x + 9
-------------------------
0 = 0 -18
0 = -18
This is never true so there are no solutions
Answer:
for kahn academy -- b -- ( no solutions)
Step-by-step explanation:
Solve the following system of equations. Express your answer as an ordered
pair in the format (a,b), with no spaces between the numbers or symbols.
2x+7y=-7
-4x-3y=-19
Answer:
(7, -3)
Step-by-step explanation:
Isolate x for 2x +7y = -7:
x = (-7 - 7y)/2
Substitute:
-4((-7 - 7y) / 2) - 3y = -19
Solve for y:
-2(-7y - 7) - 3y =
14y + 14 - 3y =
11y + 14 = -19
11y = -33
y = -3
Substitute -3:
x = (-7 - 7(-3))/2
= 14/2
x = 7
Answer:
(7,-3)
Step-by-step explanation:
What is the x-intercept of the graph?
Answer: (6,0)
Step-by-step explanation: To find the x-intercept, we plug a 0 in for y.
So we have 2x - 3(0) = 12.
Simplifying from here, we have 2x = 12.
Now divide both sides by 2 and we get x = 6.
So our x-intercept is 6.
This means that our line crosses the x-axis 6
units to the right of the origin or at the point (6,0).
Answer:
(6,0)
Step-by-step explanation:
The x intercept is where the graph crosses the x axis
Albert is growing tomato plants and studying their heights. He measured Plant A at 3 7/8 feet. He measure Plant B at 2 1/4 feet. He said that Plant B is 1 6/4 feet smaller than Plant A. Is Albert correct? Why or Why not?
Answer: Albert is wrong
Step-by-step explanation:
You first have to subtract Plant B's measurement from Plant A's measurement.
3 7/8-2 1/4 => 3 7/8-2 2/8
If you solve it you get 1 5/8. Since it cannot be reduced this is the final answer.
I NEED HELP PLEASE, THANKS! :)
A discus is thrown from a height of 4 feet with an initial velocity of 65 ft/s at an angle of 44° with the horizontal. How long will it take for the discus to reach the ground? (Show work)
Answer:
2.908 s
Step-by-step explanation:
The "work" is most easily done by a graphing calculator. We only need to tell it the equation of motion.
For speeds in feet per second, the appropriate equation for vertical ballistic motion is ...
h(t) = -16t² +v₀t +s₀
where v₀ is the initial vertical velocity in ft/s and s₀ is the initial height in feet. The vertical velocity is the vertical component of the initial velocity vector, so is (65 ft/s)(sin(44°)). We want to find t for h=0.
0 = -16t² +65sin(44°) +4
Dividing by -16 gives ...
0 = t^2 -2.82205t -0.2500
Using the quadratic formula, we find ...
t ≈ (2.82205 ±√(2.82205² -4(1)(-0.25))/2 ≈ 1.41103 +√2.24099
t ≈ 2.90802
It will take about 2.908 seconds for the discus to reach the ground.
_____
Comment on the question
You're apparently supposed to use the equation for ballistic motion even though we know a discus has a shape that allows it to "fly". It doesn't drop like a rock would.