Question 1

Which of the following has a chi-square distribution?

Accepted Answer

A)  (n - 1)σ2/s2. 
B)  (n - 1)σ/s. 
C)  (n - 1)s/σ. 
D)  (n - 1)s2/σ2. 
A)  (n - 1)σ2/s2. 
B)  (n - 1)σ/s. 
C)  (n - 1)s/σ. 
D)  (n - 1)s2/σ2.

Question 2

The manager of the service department of a local car dealership has noted that the service times of a sample of 30 new automobiles has a standard deviation of 6 minutes.A 95% confidence interval estimate for the standard deviation of the service times (in minutes) for all their new automobiles is

Accepted Answer

A)  16.047 to 45.722. 
B)  4.778 to 8.066. 
C)  2.93 to 6.31. 
D)  22.833 to 65.059. 
A)  16.047 to 45.722. 
B)  4.778 to 8.066. 
C)  2.93 to 6.31. 
D)  22.833 to 65.059.

Question 3

The contents of a sample of 26 cans of apple juice showed a standard deviation of .06 ounces.We are interested in testing whether the variance of the population is significantly more than .003.The p-value for this test is

Accepted Answer

A)  .05. 
B)  greater than .10. 
C)  less than .10. 
D)  zero. 
A)  .05. 
B)  greater than .10. 
C)  less than .10. 
D)  zero.

Question 4

A sample of 60 items from population 1 has a sample variance of 8 while a sample of 40 items from population 2 has a sample variance of 10.If we want to test whether the variances of the two populations are equal, the test statistic will have a value of

Accepted Answer

A)  .8. 
B)  1.56. 
C)  1.5. 
D)  1.25. 
A)  .8. 
B)  1.56. 
C)  1.5. 
D)  1.25.

Question 5

The contents of a sample of 26 cans of apple juice showed a standard deviation of .06 ounces.We are interested in testing whether the variance of the population is significantly more than .003.At the .05 level of significance, the null hypothesis

Accepted Answer

A)  should be rejected. 
B)  should not be rejected. 
C)  should be revised. 
D)  should not be tested. 
A)  should be rejected. 
B)  should not be rejected. 
C)  should be revised. 
D)  should not be tested.

Question 6

A sample of 20 cans of tomato juice showed a standard deviation of .4 ounces.A 95% confidence interval estimate of the variance for the population is

Accepted Answer

A)  .2313 to .8533. 
B)  .2224 to .7924. 
C)  .3042 to .5843. 
D)  .0925 to .3413. 
A)  .2313 to .8533. 
B)  .2224 to .7924. 
C)  .3042 to .5843. 
D)  .0925 to .3413.

Question 7

The producer of a certain medicine claims that their bottling equipment is very accurate and that the standard deviation of all their filled bottles is .1 ounces or less.A sample of 20 bottles showed a standard deviation of .11 ounces.The test statistic to test the claim is

Accepted Answer

A)  2.3. 
B)  22.99. 
C)  4.85. 
D)  24.2. 
A)  2.3. 
B)  22.99. 
C)  4.85. 
D)  24.2.

Question 8

Consider the following hypothesis problem. $$\begin{array} { l l } 
n = 14 & H _ { 0 } : \sigma ^ { 2 } \leq 410 \
s = 20 & H _ { \mathrm { a } } : \sigma ^ { 2 } > 410
\end{array}$$   At the 5% level of significance, the null hypothesis

Accepted Answer

A)  should be rejected 
B)   should not be rejected 
C)   should be revised. 
D)  should not be tested. 
A)  should be rejected 
B)   should not be rejected 
C)   should be revised. 
D)  should not be tested.

Question 9

The chi-square value for a one-tailed (lower tail) test when the level of significance is .1 and the sample size is 15 is

Accepted Answer

A)  21.064. 
B)  23.685. 
C)  7.790. 
D)  6.571. 
A)  21.064. 
B)  23.685. 
C)  7.790. 
D)  6.571.

Question 10

The value of F.05 with 8 numerator and 19 denominator degrees of freedom is

Accepted Answer

A)  2.48. 
B)  2.58. 
C)  3.63. 
D)  2.96. 
A)  2.48. 
B)  2.58. 
C)  3.63. 
D)  2.96.

Question 11

Consider the following hypothesis problem.  $\begin{array}{lll}
n=23 & s^{2}=60 & H_{0}: \sigma^{2}=66 \
&& H_{\mathrm{a}}: \sigma^{2}>66
\end{array}$  
The p-value is

Accepted Answer

A)  less than .025. 
B)  between .025 and .05. 
C)  between .05 and .10. 
D)  greater than .10. 
A)  less than .025. 
B)  between .025 and .05. 
C)  between .05 and .10. 
D)  greater than .10.

Question 12

To avoid the problem of not having access to tables of the F distribution when a one-tailed test is required and with F values given for the lower tail, let​ the

Accepted Answer

A)  smaller sample variance be the numerator of the test statistic. 
B)  larger sample variance be the numerator of the test statistic. 
C)  sample variance from the population with the smaller hypothesized variance be the numerator of the test statistic. 
D)  sample variance from the population with the larger hypothesized variance be the numerator of the test statistic. 
A)  smaller sample variance be the numerator of the test statistic. 
B)  larger sample variance be the numerator of the test statistic. 
C)  sample variance from the population with the smaller hypothesized variance be the numerator of the test statistic. 
D)  sample variance from the population with the larger hypothesized variance be the numerator of the test statistic.

Question 13

The producer of a certain bottling equipment claims that the variance of all their filled bottles is .027 or less.A sample of 30 bottles showed a standard deviation of .2 ounces.The p-value for the test is

Accepted Answer

A)  between .025 to .05. 
B)  between .05 to .10. 
C)  .05. 
D)  .025. 
A)  between .025 to .05. 
B)  between .05 to .10. 
C)  .05. 
D)  .025.

Question 14

Consider the following hypothesis problem. $\begin{array}{lll}
n=23 & s^{2}=60 & H_{0}: \sigma^{2}=66 \
&& H_{\mathrm{a}}: \sigma^{2}>66
\end{array}$ 
 The test statistic has a value of

Accepted Answer

A)  20.91. 
B)  24.20. 
C)  24.00. 
D)  20.00. 
A)  20.91. 
B)  24.20. 
C)  24.00. 
D)  20.00.

Question 15

For an F distribution, the number of degrees of freedom for the numerator

Accepted Answer

A)  must be larger than the number of degrees of freedom for the denominator. 
B)  must be smaller than the number of degrees of freedom for the denominator. 
C)  must be equal to the number of degrees of freedom for the denominator. 
D)  can be larger, smaller, or equal to the number of degrees of freedom for the denominator. 
A)  must be larger than the number of degrees of freedom for the denominator. 
B)  must be smaller than the number of degrees of freedom for the denominator. 
C)  must be equal to the number of degrees of freedom for the denominator. 
D)  can be larger, smaller, or equal to the number of degrees of freedom for the denominator.

Question 16

The contents of a sample of 26 cans of apple juice showed a standard deviation of .06 ounces.We are interested in testing whether the variance of the population is significantly more than .003.The null hypothesis is

Accepted Answer

A)  s2 > .003. 
B)  s2 ≤ .003. 
C)  σ2 > .003. 
D)  σ2 ≤ .003. 
A)  s2 > .003. 
B)  s2 ≤ .003. 
C)  σ2 > .003. 
D)  σ2 ≤ .003.

Question 17

Consider the following hypothesis problem. $$\begin{array} { l l } 
n = 14 & H _ { 0 } : \sigma ^ { 2 } \leq 410 \
s = 20 & H _ { \mathrm { a } } : \sigma ^ { 2 } > 410
\end{array}$$  The test statistic equals

Accepted Answer

A)  .63. 
B)   12.68. 
C)   13.33. 
D)   13.68. 
A)  .63. 
B)   12.68. 
C)   13.33. 
D)   13.68.

Question 18

The bottler of a certain soft drink claims their equipment to be accurate and that the variance of all filled bottles is .05 or less.The null hypothesis in a test to confirm the claim would be written as

Accepted Answer

A)  H0: σ2 ≥ .05. 
B)  H0: σ2 > .05. 
C)  H0: σ2 0: σ2 ≤ .05. 
A)  H0: σ2 ≥ .05. 
B)  H0: σ2 > .05. 
C)  H0: σ2 0: σ2 ≤ .05.

Question 19

The random variable for a chi-square distribution may assume

Accepted Answer

A)  any value between -1 to 1. 
B)  any value between -∞ to +∞. 
C)  any negative value. 
D)  any value greater than zero. 
A)  any value between -1 to 1. 
B)  any value between -∞ to +∞. 
C)  any negative value. 
D)  any value greater than zero.

Question 20

The 95% confidence interval estimate of a population variance when a sample variance of 324 is obtained from a sample of 81 items is

Accepted Answer

A)  14.14 to 174.94. 
B)  243.086 to 453.520. 
C)  16.42 to 194.35. 
D)  254.419 to 429.203. 
A)  14.14 to 174.94. 
B)  243.086 to 453.520. 
C)  16.42 to 194.35. 
D)  254.419 to 429.203.

Which of the following has a chi-square distribution?

The manager of the service department of a local car dealership has noted that the service times of a sample of 30 new automobiles has a standard deviation of 6 minutes.A 95% confidence interval estimate for the standard deviation of the service times (in minutes) for all their new automobiles is

The contents of a sample of 26 cans of apple juice showed a standard deviation of .06 ounces.We are interested in testing whether the variance of the population is significantly more than .003.The p-value for this test is

A sample of 60 items from population 1 has a sample variance of 8 while a sample of 40 items from population 2 has a sample variance of 10.If we want to test whether the variances of the two populations are equal, the test statistic will have a value of

The contents of a sample of 26 cans of apple juice showed a standard deviation of .06 ounces.We are interested in testing whether the variance of the population is significantly more than .003.At the .05 level of significance, the null hypothesis

A sample of 20 cans of tomato juice showed a standard deviation of .4 ounces.A 95% confidence interval estimate of the variance for the population is

The producer of a certain medicine claims that their bottling equipment is very accurate and that the standard deviation of all their filled bottles is .1 ounces or less.A sample of 20 bottles showed a standard deviation of .11 ounces.The test statistic to test the claim is

Consider the following hypothesis problem. n=14 :\leq410 s=20 :>410 At the 5% level of significance, the null hypothesis

The chi-square value for a one-tailed (lower tail) test when the level of significance is .1 and the sample size is 15 is

The value of F_.05 with 8 numerator and 19 denominator degrees of freedom is

Consider the following hypothesis problem. n=23 =60 :=66 :>66 The p-value is

To avoid the problem of not having access to tables of the F distribution when a one-tailed test is required and with F values given for the lower tail, let the

The producer of a certain bottling equipment claims that the variance of all their filled bottles is .027 or less.A sample of 30 bottles showed a standard deviation of .2 ounces.The p-value for the test is

Consider the following hypothesis problem. n=23 =60 :=66 :>66 The test statistic has a value of

For an F distribution, the number of degrees of freedom for the numerator

The contents of a sample of 26 cans of apple juice showed a standard deviation of .06 ounces.We are interested in testing whether the variance of the population is significantly more than .003.The null hypothesis is

Consider the following hypothesis problem. n=14 :\leq410 s=20 :>410 The test statistic equals

The bottler of a certain soft drink claims their equipment to be accurate and that the variance of all filled bottles is .05 or less.The null hypothesis in a test to confirm the claim would be written as

The random variable for a chi-square distribution may assume

The 95% confidence interval estimate of a population variance when a sample variance of 324 is obtained from a sample of 81 items is

Data and Statistics

Descriptive Statistics: Tabulargraphical

Descriptive Statistics: Numerical

Introduction to Probability

Discrete Probability Distributions

Continuous Probability Distributions

Sampling and Sampling Distributions

Interval Estimation

Hypothesis Tests

Inference About Means and Proportions With Two Populations

Comparing Multiple Proportions, Test of Independence and Goodness of Fit

Experimental Design and Analysis of Variance

Simple Linear Regression

Multiple Regression

Filters

Exam 11: Inferences About Population Variances

Which of the following has a chi-square distribution?

The manager of the service department of a local car dealership has noted that the service times of a sample of 30 new automobiles has a standard deviation of 6 minutes.A 95% confidence interval estimate for the standard deviation of the service times (in minutes) for all their new automobiles is

The contents of a sample of 26 cans of apple juice showed a standard deviation of .06 ounces.We are interested in testing whether the variance of the population is significantly more than .003.The p-value for this test is

A sample of 60 items from population 1 has a sample variance of 8 while a sample of 40 items from population 2 has a sample variance of 10.If we want to test whether the variances of the two populations are equal, the test statistic will have a value of

The contents of a sample of 26 cans of apple juice showed a standard deviation of .06 ounces.We are interested in testing whether the variance of the population is significantly more than .003.At the .05 level of significance, the null hypothesis

A sample of 20 cans of tomato juice showed a standard deviation of .4 ounces.A 95% confidence interval estimate of the variance for the population is

The producer of a certain medicine claims that their bottling equipment is very accurate and that the standard deviation of all their filled bottles is .1 ounces or less.A sample of 20 bottles showed a standard deviation of .11 ounces.The test statistic to test the claim is

Consider the following hypothesis problem. n=14 :\leq410 s=20 :>410 At the 5% level of significance, the null hypothesis

The chi-square value for a one-tailed (lower tail) test when the level of significance is .1 and the sample size is 15 is

The value of F.05 with 8 numerator and 19 denominator degrees of freedom is

Consider the following hypothesis problem. n=23 =60 :=66 :>66 The p-value is

To avoid the problem of not having access to tables of the F distribution when a one-tailed test is required and with F values given for the lower tail, let​ the

The producer of a certain bottling equipment claims that the variance of all their filled bottles is .027 or less.A sample of 30 bottles showed a standard deviation of .2 ounces.The p-value for the test is

Consider the following hypothesis problem. n=23 =60 :=66 :>66 The test statistic has a value of

For an F distribution, the number of degrees of freedom for the numerator

The contents of a sample of 26 cans of apple juice showed a standard deviation of .06 ounces.We are interested in testing whether the variance of the population is significantly more than .003.The null hypothesis is

Consider the following hypothesis problem. n=14 :\leq410 s=20 :>410 The test statistic equals

The bottler of a certain soft drink claims their equipment to be accurate and that the variance of all filled bottles is .05 or less.The null hypothesis in a test to confirm the claim would be written as

The random variable for a chi-square distribution may assume

The 95% confidence interval estimate of a population variance when a sample variance of 324 is obtained from a sample of 81 items is

Data and Statistics

Descriptive Statistics: Tabulargraphical

Descriptive Statistics: Numerical

Introduction to Probability

Discrete Probability Distributions

Continuous Probability Distributions

Sampling and Sampling Distributions

Interval Estimation

Hypothesis Tests

Inference About Means and Proportions With Two Populations

Comparing Multiple Proportions, Test of Independence and Goodness of Fit

Experimental Design and Analysis of Variance

Simple Linear Regression

Multiple Regression

Filters

The value of F_.05 with 8 numerator and 19 denominator degrees of freedom is

To avoid the problem of not having access to tables of the F distribution when a one-tailed test is required and with F values given for the lower tail, let the