1. The margin of error in estimating the population mean of a normal population isE= 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.

a)

Smaller.Edecreases as the square root of the sample size gets larger.

b)

Smaller.Eincreases as the square root of the sample size gets larger.

c)

Larger.Edecreases as the square root of the sample size gets larger.

d)

Larger.Eincreases as the square root of the sample size gets larger.

1. A golfer wished to find a ball that would travel more than 200 yards when hit with his 4-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 9 times at the required speed. State the null and alternative hypotheses for this test.

a)

H₀: < 200; H_a: = 200

b)

H₀: = 200; H_a: < 200

c)

H₀: > 200; H_a: > 200

d)

H₀: = 200; H_a: > 200

1. A 95% confidence interval for the mean of a normal population is found to be 17.6 < < 23.6. What is the margin of error?

a)

2.0

b)

2.7

c)

3.0

d)

4.0

1. 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 ²statistic for the chart data.

a)

1.325

b)

1.318

c)

1.286

d)

1.264

1. The margin of error in estimating the population mean of a normal population isE= 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.

a)

Smaller.Edecreases as the square root of the sample size gets larger.

b)

Smaller.Eincreases as the square root of the sample size gets larger.

c)

Larger.Edecreases as the square root of the sample size gets larger.

d)

Larger.Eincreases as the square root of the sample size gets larger.

1. The critical value of ²for a 2 x 2 table using a 0.05 significance level is 3.841. If the value of the ²statistic in a test for the dependence of colorblindness on gender had been 4.613, state your conclusion about the relationship between gender and colorblindness.

a)

Reject H₀. There's not sufficient evidence to support the claim that gender and colorblindness are related.

b)

Reject H₀. There's sufficient evidence to support the claim that gender and colorblindness are related.

c)

Don't Reject H₀. There's sufficient evidence to support the claim that gender and colorblindness are related.

d)

Don't Reject H₀. There's not sufficient evidence to support the claim that gender and colorblindness are related.