Answer:
Explained below.
Step-by-step explanation:
The claim made by an expert is that driving conditions are dangerous if the variance of speeds exceeds 75 (mph)².
(1)
The hypothesis for both the test can be defined as:
H₀: The variance of speeds does not exceeds 75 (mph)², i.e. σ² ≤ 75.
Hₐ: The variance of speeds exceeds 75 (mph)², i.e. σ² > 75.
(2)
A Chi-square test will be used to perform the test.
The significance level of the test is, α = 0.05.
The degrees of freedom of the test is,
df = n - 1 = 55 - 1 = 54
Compute the critical value as follows:
[tex]\chi^{2}_{\alpha, (n-1)}=\chi^{2}_{0.05, 54}=72.153[/tex]
Decision rule:
If the test statistic value is more than the critical value then the null hypothesis will be rejected and vice-versa.
(3)
Compute the test statistic as follows:
[tex]\chi^{2}=\frac{(n-1)\times s^{2}}{\sigma^{2}}[/tex]
[tex]=\frac{(55-1)\times 94.7}{75}\\\\=68.184[/tex]
The test statistic value is, 68.184.
Decision:
[tex]cal.\chi^{2}=68.184<\chi^{2}_{0.05,54}=72.153[/tex]
The null hypothesis will not be rejected at 5% level of significance.
Conclusion:
The variance of speeds does not exceeds 75 (mph)². Thus, concluding that driving conditions are not dangerous on this highway.
In an effort to make children’s toys safer and more tamperproof, toy packaging has become cumbersome for parents to remove in many cases. Accordingly, the director of marketing at Toys4Tots, a large toy manufacturer, wants to evaluate the effectiveness of a new packaging design that engineers claim will reduce customer complaints by more than 10 percentage points. Customer satisfaction surveys were sent to 220 parents who registered toys packaged under the old design and 220 parents who registered toys packaged under the new design. Of these, 86 parents expressed dissatisfaction with packaging of the old design, and 41 parents expressed dissatisfaction with packaging of the new design.
Let p1 represent the population proportion of parents that expressed dissatisfaction with the packaging of the old design and p2 represent the population proportion of parents that expressed dissatisfaction with the packaging of the new design.
A. Specify the null and alternative hypotheses to test for whether the proportion of customer complaints has decreased by more than 5% under the new packaging design.
1. H0 : p1 - p2 < 0.10; HA : p1 - p2 > 0.10
2. H0 : p1 - p2 = 0.10; HA : p1 - p2 is not equal to 0.10
3. H0 : p1 - p2 > 0.10; HA : p1 - p2 < 0.10
B. What is the value of the test statistic and the associated p-value?
C. At the 1% significance level, do the results support the engineers' claim?
D. At the 10% significance level, do the results support the engineers' claim?
Answer:
Explained below.
Step-by-step explanation:
(a)
In this case we need to determine if the proportion of customer complaints has decreased by more than 10% under the new packaging design.
The hypothesis can be defined as follows:
H₀: The proportion of customer complaints has not decreased by more than 10% under the new packaging design, i.e. p₁ - p₂ ≤ 0.10.
Hₐ: The proportion of customer complaints has decreased by more than 10% under the new packaging design, i.e. p₁ - p₂ > 0.10.
(b)
The information provided is:
n₁ = 220
n₂ = 220
X₁ = 86
X₂ = 41
Compute the sample proportions and total proportions as follows:
[tex]\hat p_{1}=\frac{X_{1}}{n_{1}}=\frac{86}{220}=0.3909\\\\\hat p_{2}=\frac{X_{2}}{n_{2}}=\frac{41}{220}=0.1864\\\\\hat P=\frac{X_{1}+X_{2}}{n_{1}+n_{2}}=\frac{86+41}{220+220}=0.2886[/tex]
Compute the test statistic value as follows:
[tex]z=\frac{\hat p_{1}-\hat p_{2}}{\sqrt{\hat P(1-\hat P)[\frac{1}{n_{1}}+\frac{1}{n_{2}}]}}[/tex]
[tex]=\frac{0.3909-0.1864}{\sqrt{0.2886(1-0.2886)\times[\frac{1}{220}+\frac{1}{220}]}}\\\\=\frac{0.2045}{\sqrt{0.0018665}}\\\\=4.733524\\\\\approx 4.73[/tex]
The test statistic value is 4.73.
Compute the p-value as follows:
[tex]p-value=P(Z>4.73)[/tex]
[tex]=1-P(Z<4.73)\\=1-(\approx 1)\\=0[/tex]
The p-value of the test is 0.
(c)
The decision rule is:
The null hypothesis will be rejected if the p-value of the test is less than the significance level.
p-value = 0 < α = 0.01.
The null hypothesis will be rejected at 1%significance level.
Thus, there is enough evidence at 1% significance level to support the engineers' claim.
(d)
The decision rule is:
The null hypothesis will be rejected if the p-value of the test is less than the significance level.
p-value = 0 < α = 0.10.
The null hypothesis will be rejected at 10%significance level.
Thus, there is enough evidence at 10% significance level to support the engineers' claim.
answer for brainliest ! <3
Answer:
1: p=(2,4) q=(1,1) r=(5,2)
2 I am so sorry. the changing in the shape is not any transformation I've heard of before.
3:90 degree rotation (Counterclockwise.)
4: 180 degree rotation (doesn't matter which way.)
5: 90 degree rotation (clockwise)
6: Up 9 units, over 2 units to the right.
Hope this helps!!
Find value of x, first gets brain
Answer:
53
Step-by-step explanation:
Find the value of x.
(7x + 16)
80°
The value of x is
What is 200 as a percent?
Answer:
Step-by-step explanation:
So, we know that 200 can also be written as 200.00 which does not change the value of the number. Now, we can turn it into a percentage by moving the decimal point to digits back: 200.00 --> 20000. So, this means that 200 is 20000%.
hello I need help on it please
Answer: Adams heart Beats 1,440 more times than Blake’s in 120 minutes.
Step-by-step explanation:
Adam: 74 x 120 = 8,880
Blake: 62 x 120 = 7,440
8,880 - 7,440 = 1,440
Answer:
1440
Step-by-step explanation: you multiply
74 x 120 and 62 x 120
8,880 7,440 then subtract the two
8,880 - 7,740 = 1,440
Write and expression equivalent to - 1/2(6x-8+4x please help
Step-by-step explanation:
I won't say the answer, but will give an explanation. the explanation for solving the expression is above.
the fully simplified expression is 5x - 4. All you need to do now is make an expression that will equal 5x - 4 simplified.
An example is: 20(1/4x-1/5)
if I read the questions wrong and it's just asking to simplify the expression then the answer is 5x - 4.
Find the value of x:
PLEASE HELP!!! ILL GIVE BRAINLIEST
Answer:
118 degrees
Step-by-step explanation:
Answer:
118°
Step-by-step explanation:
62 and angle B are supplementary angles, so they add up to 180. 180-62 is 118, so angle B is 118.
Tanmayi wants to raise $190 for a school fundraiser. She has raised $140 so far. How much more does she need to reach her goal? Let m be how much more is needed.
Answer:
190 plus x = 140 -140 -140 x=50During the 2005 football season Team Tackle beat Team Sack by 18 points their combined scores totaled 66. the individual team score
1. Team tackles score was ? Points
2. Team sacks score was ? Points
Please help me I have no idea what the answer is
Answer:
hi
Step-by-step explanation:
make -4 a fraction
Answer:
4/1
Step-by-step explanation:
like 1 is like 1 whole
Answer:
-16/4
Step-by-step explanation:
In this way it will be in fraction
-16/4
which means, -16÷4= -4
6TH GRADE MATH!!
Sheila can ride are bicycle 6,000 meters in 15 minutes. Cal can ride his bicycle 3,400 meters in 8 minutes.Select true or false for the following statement. cal can ride his bicycle 750 meters in 1 minutes.
Answer:
false
Step-by-step explanation:
to get this answer you need to divide 3,400 by 8. Which is 425. So no, he can not go 750 meters, he can only go 425 meters in one minute. hope this helps!!
Consider the sequence of steps to solve the equation:
7x
5(x - 3) =
Step 1 = 10(x - 3) = 7x
Step 2 = 10x - 30 = 7x
Step 3 = 3x - 30 = 0
Step 4 = 3x = 30
Step 5 = x= 10
Identify the property of equality which yields Step 5.
A)
Division Property
B)
Addition Property
C)
Subtraction Property
D)
Multiplication Property
Robert and Dora need to write 4,300,000,000 using scientific notation. Robert claims that 4,300,000,000 = 4.3 x 108 and Dora claims that 4,300,000,000 = 4.3 x 109. Which of the following best describes whose number is correct and the reason it is correct?
Answer:
Robert is correct
Step-by-step explanation:
we know in scientific notation a positive number goes to the right and if we do 4.3 and we go back the spaces it would be nine spaces so it would be 4.3 X 109
Evaluate the following expression.
50÷ 5^2×2
How are the different representations of a function used to determine
the relationship between the quantities?
Answer:
Step-by-step explanation:
A function can be represented verbally. For example, the circumference of a square is four times one of its sides.
A function can be represented algebraically. For example, 3x+6 3 x + 6 .
A function can be represented numerically.
A function can be represented graphically.
There are three ways in which representations of a function are used to determine are, algebraic, numerical, and graphical .
Given that,
To explain the way the representation of a function for the relationship between quantities.
Functions are the relationship between sets of values. e g y=f(x), for every value of x there is its exists in a set of y. x is the independent variable while Y is the dependent variable.
Here,
There are three ways in which the representations of a function are used to determine the relationship between the quantities,
(a) algebraic, (b) numerical, and (c) graphical.
Thus, there are three ways, algebraic, numerical, and graphical.
learn more about function here:
brainly.com/question/21145944
#SPJ2
what is 2+2x2
ill give brainliest to the person that gets it correct
Answer:6
Step-by-step explanation:
Answer:
6.............................
Step-by-step explanation:
Bill lent some money to his two brothers. He wrote down the amounts so he would not forget. The list shows the younger brother with −$17.25 and the older brother with $0. Which of the following statements best describes the amounts?
The older brother paid Bill $17.25, and the younger brother does not owe him any money.
The older brother owes Bill $17.25, and the younger brother does not owe him any money.
The younger brother owes Bill $17.25, and the older brother does not owe him any money.
The younger brother paid Bill $17.25, and the older brother does not owe him any money.
Answer:
the younger brother owes bill $17.25, and the older brother dose not owe him anything
Answer:
i got it right on the trst
Step-by-step explanation:
3 new tires for $210; 4 new tires for $250
how can you work with anybody annoying you white your working at home on a test?
Which of the following functions has a graph that passes through the origin? Select all that apply.
A. power; y equals x superscript n baseline
B. root; y equals Root Index n Start Root x End Root
C. reciprocal; y equals Start Fraction 1 over x End Fraction
D. exponential; y equals b superscript x baseline
Answer: a and b
power and root
In the picture lines AB and CD are parallel. Find the measures of
the following angles. Explain your reasoning.
F
E
D
В.
38 A.
1. BCD
2. ZECF
3. ZDCF
Answer/Step-by-step explanation:
1. <ABC and <BCD are alternate interior angles. Alternate interior angles are equal, therefore, since m<ABC = 38°, then m<BCD = 38°
2. m<ECF = m<BCD (corresponding angles)
m<ECF = 38° (substitution)
3. m<DCF + m<ECF = 180° (linear pair)
m<DCF + 38° = 180° (substitution)
m<DCF = 180° - 38° (Subtraction property of equality)
m<DCF = 142°
-2x^2-20x-46
How would you solve this?
Answer:
-2x^2-20x-46
Step-by-step explanation:
-2(x^2)-20x-46
-2(x^2) -2(10x)-46
-2(x^2)-2(10x)-2(23)
-2(x^2+10x)-2(23)
-2x^2-20x-46
3+3+3
Please Help....
Answer:
9
Step-by-step explanation:
I need help! Find the equation of a line parallel to 3x-3y=5 that contains the point (-1,-5). Write the equation in slope Intercept form.
the equation of the line is y= x-4
Step-by-step explanation:
so so the first thing that you're going to do is get y alone
-x-5=y
next you're going to find your slope which in this case is negative one.
after that in order to find the equation of a parallel line you're going to find the reciprocal of the slope.
so in this case the reciprocal is one.
next you're going to substitute in the cordinates to find the y intercept
x+b=y. (-1)+b= -5. (. b is the y intercept)
b= -4
A is an angle in standard position and satisfies the given conditions. Find the indicated trigonometric function value of A.
The terminal side of A is in quadrant II and lies on the line -7x - 5y = 0.
Find sec A.
9514 1404 393
Answer:
sec(A) = -(1/5)√74
Step-by-step explanation:
Solving the equation for y, we have ...
-7x = 5y
-7/5x = y
The slope of this line (-7/5) is the tangent of the angle (A) it makes with the x-axis. The secant satisfies the relation ...
sec(A)^2 = 1 + tan(A)^2
sec(A) = √(1 +tan(A)^2)
sec(A) = -√(1 +(-7/5)^2) = -√(74/25) . . . . secant is negative in 2nd quadrant
sec(A) = -(1/5)√74
which set of numbers are equivalent
0.32 , 32% , 1/32
0.45 , 50% ,49/50
0.30, 30% , 30/300
0.15 , 15% , 30/200
i will give you 40 pionts
A VISA CARD HAS A 3% CASH BACK BONUS FOR GAS AND A 1% CASH BACK FOR EVERYTHING ELSE. THIS MONTH YOU SPENT $1,500. 1/3 WAS FOR GAS.wHAT WAS YOURCASH BACK BONUS?
Answer:
25 Dollars Cashback Bonus
Step-by-step explanation:
Lets determine both Gas CashBack (x) and Non-Gas CashBack (y) first:
x = 500 (1500 times 1/3 is 500) times .03 = 15
y = 1000 (1500 minus 500) times .01 = 10
x (15) + y (10) = 25