Question 1 5 / 5 points
The following data were analyzed using one-way analysis of variance.
A B C
34 27 19
26 23 31
31 29 22
28 21 22
Which one of the following statements is correct?
a) The purpose of the analysis is to determine whether the groups A, B, and C are independent.
b) The purpose of the analysis is to test the hypothesis that the population means of the three groups are equal.
c) The purpose of the analysis is to test the hypothesis that the population variances of the three groups are equal.
d) The purpose of the analysis is to test the hypothesis that the sample means of the three groups are equal.
Question 2 5 / 5 points
A golfer wished to find a ball that would travel more than 170 yards when hit with his 6-iron with a club head speed of 90 miles per hour. He had a golf equipment lab test a low-compression ball by having a robot swing his club 12 times at the required speed. State the null and alternative hypotheses for this test.
Question 3 5 / 5 points
State the null and alternative hypothesis for the test associated with testing whether colorblindness and gender are dependent characteristics.
Question 4 5 / 5 points
A golfer wished to find a ball that would travel more than 160 yards when hit with his 7-iron with a club speed of 90 miles per hour. He had a golf equipment lab test a low-compression ball by having a robot swing his club 8 times at the required speed. State the null and alternative hypotheses for this test.
Question 5 5 / 5 points
One hundred people are selected at random and tested for colorblindness to determine whether gender and colorblindness are independent. The following counts were observed.
Colorblind Not Colorblind Total
Male 8 52 60
Female 2 38 40
Total 10 90 100
Find the value of the χ2 statistic for the data.
a) 1.463
b) 1.852
c) 1.947
d) 1.949
Question 6 5 / 5 points
One hundred people are selected at random and tested for colorblindness to determine whether gender and colorblindness are independent. The following counts were observed.
Colorblind Not Colorblind Total
Male 7 53 60
Female 1 39 40
Total 8 92 100
Find the value of the χ2 statistic for the chart data.
Question 7 5 / 5 points
A 95% confidence interval for the mean of a normal population is found to be 13.2 < µ < 22.4. What is the margin of error?
Question 8 5 / 5 points
The following data were analyzed using one-way analysis of variance.
A B C
24 27 19
26 23 31
31 29 27
28 31 22
Which one of the following statements is correct?
a) The purpose of the analysis is to determine whether the groups A, B, and C are independent.
b) The purpose of the analysis is to test the hypothesis that the population means of the three groups are equal.
c) The purpose of the analysis is to test the hypothesis that the population variances of the three groups are equal.
d) The purpose of the analysis is to test the hypothesis that the sample means of the three groups are equal.
Question 9 5 / 5 points
A golfer wished to find a ball that would travel more than 180 yards when hit with his 5-iron with a club speed of 90 miles per hour. He had a golf equipment lab test a low-compression ball by having a robot swing his club 7 times at the required speed. State the null and alternative hypotheses for this test.
Question 10 5 / 5 points
A 95% confidence interval for the mean of a normal population is found to be 17.6 < µ < 23.6. What is the margin of error?
Question 11 5 / 5 points
Which of the following statements is true?
a) The p distribution can’t be used when finding a confidence interval for the population mean with a small sample anytime the population standard deviation is unknown.
b) The t distribution can be used when finding a confidence interval for the population mean with a small sample anytime the population standard deviation is unknown.
c) The t distribution can’t be used when finding a confidence interval for the population mean with a small sample anytime the population standard deviation is unknown.
d) The p distribution can be used when finding a confidence interval for the population mean with a small sample anytime the population standard deviation is unknown.
Question 12 5 / 5 points
One hundred people are selected at random and tested for colorblindness to determine whether gender and colorblindness are independent. The following counts were observed.
Colorblind Not Colorblind Total
Male 8 52 60
Female 2 38 40
Total 10 90 100
If gender and colorblindness are independent, find the expected frequencies of colorblindness and non-colorblindness among 60 males. (Note: To answer this question, it may help to create your own 2 X 2 table of expected frequencies, based on the data for the random sample.)
Question 13 5 / 5 points
One hundred people are selected at random and tested for colorblindness to determine whether gender and colorblindness are independent. The following counts were observed.
Colorblind Not Colorblind Total
Male 7 53 60
Female 1 39 40
Total 8 92 100
If gender and colorblindness are independent, find the expected values corresponding to the female combinations of gender and colorblindness.
Question 14 5 / 5 points
The critical value of χ2 for a 2 x 2 table using a 0.05 significance level is 3.841. If the value of the χ2 statistic in a test for the dependence of colorblindness on gender had been 4.613, state your conclusion about the relationship between gender and colorblindness.
Question 15 5 / 5 points
State the null and alternative hypothesis for the testing whether colorblindness and gender are related.
Question 16 5 / 5 points
A large test statistic F tells us that the sample means _______ the data within the individual samples, which would be unlikely if the populations means really were equal (as the null hypothesis claims).
Question 17 5 / 5 points
The margin of error in estimating the population mean of a normal population is E = 9.3 when the sample size is 15. If the sample size had been 18 and the sample standard deviation didn’t change, would the margin of error be larger or smaller than 9.3? Explain your answer.
Question 18 0 / 5 points
Data from 8 robot swings of a 7-iron at 90 miles per hour resulted in a sample mean of 163.2 yards with a sample standard deviation of 5.8 yards. Assuming normality, carry out a hypothesis test at the 0.05 significance level to determine whether the ball meets the golfer’s required average of more than 160 yards per swing. Use the partial t-table below to solve this problem.
Area in one tail
0.025 0.05
Area in two tails
Degrees of Freedom n - 1 0.05 0.10
6 2.447 1.943
7 2.365 1.895
8 2.306 1.860
9 2.262 1.833
10 2.228 1.812
11 2.201 1.796
12 2.179 1.782
Question 19 5 / 5 points
One hundred people are selected at random and tested for colorblindness to determine whether gender and colorblindness are independent. The following counts were observed.
Colorblind Not Colorblind Total
Male 7 53 60
Female 1 39 40
Total 8 92 100
If gender and colorblindness are independent, find the expected values corresponding to the male combinations of gender and colorblindness.
Question 20 5 / 5 points
Which of the following statements is true?
a) The t distribution can be used when finding a confidence interval for the population mean whenever the sample size is small.
b) The p distribution can be used when finding a confidence interval for the population mean whenever the sample size is small.
c) The t distribution can’t be used when finding a confidence interval for the population mean whenever the sample size is small.
d) The p distribution can’t be used when finding a confidence interval for the sample mean whenever the sample size is small.
