Question

1. Do you check your phone or use technology right before you go to bed? If so, chances are that you are not alone. A recent news report claims that 60% of adults use some kind of technology right before they go to bed at night. Believing that this claimed value is too low, a researcher surveys a random sample of 200 adults and finds that 71% use some kind of right before they go to bed. If a hypothesis test is conducted in order to test the claim that Ho: p = 0.60, what will the p-value be?

A. Less than 0.01

B. Larger than 0.10

C. Between 0.01 and 0.05

D. Between 0.05 and 0.10

E. There is not enough information available in the problem to determine the p-value

2. A claim is made that Netflix customers watch an average of 10 hours of Netflix programming during a typical week. A marketing firm questions this claim. They survey a random sample of 120 Netflix customers and find these customers watch an average of 12 hours of Netflix programming during a typical week, with a sample standard deviation of 8.4 hours. Based on this information, what will the test statistic be? Choose the answer below that is closest to what you calculate, and try not to do a lot of rounding until you get to the very end of your calculations.

A. Smaller than 1

B. 1.2

C. 2.6

D. 3.7

E. Larger than 5

3. Which of the following statements is false?

A. A small p-value can lead to a result that is statistically significant but not practically important.
B. We say a result is practically significant if the result would be unlikely to occur just by chance alone if we assume the null hypothesis is true.

C. It is not necessary to know the alpha (or significance) level in order to compute the p-value.

D. A p-value is a probability.

E. None of the above answer choices are false.

4. Are people waiting until they are older to get married? According to a recent report, 38% of adults wait until they are 30 years of age or older to get married for the first time. A sociologist questions this claim. She surveys a random sample of 586 married adults and learns that 26% of the individuals in the sample waited until they were 30 years of age or older to get married. What would the sample proportion be?

A. 0.04

B. 0.17

C. 0.26

D. 0.38

E. 0.59

Answer 1

1.

Standard error = sqrt(0.6 * (1-0.6)/200) = 0.03464102

Test statistic, z = (0.71 - 0.6)/0.03464102 = 3.18

P-value = P(z > 3.18) = 0.0007

A. Less than 0.01

2.

Standard error = 8.4/sqrt(120) = 0.7668116

Test statistic, t = (12-10)/0.7668116 = 2.6

C. 2.6

3.

The false statement is,

B. We say a result is practically significant if the result would be unlikely to occur just by chance alone if we assume the null hypothesis is true.

The correct statement is,

We say a result is statistically significant if the result would be unlikely to occur just by chance alone if we assume the null hypothesis is true.

4.

sample proportion = 26% = 0.26

C. 0.26