30. The mean monthly gasoline bill for one household is greater than $120. If a hypothesis test is performed, how should you interpret a decision that fails to reject the null hypothesis?

There is sufficient evidence to reject the claim > $120.

There is not sufficient evidence to support the claim > $120.

There is not sufficient evidence to reject the claim > $120.

There is sufficient evidence to support the claim > $120.

31. When the results of a hypothesis test are determined to be statistically significant, then we _______________ the null hypothesis.

reject

compartmentalize

fail to reject

polarize

32. A survey claims that 9 out of 10 doctors (i.e., 90%) recommend brand Z for their patients who have children. To test this claim against the alternative that the actual proportion of doctors who recommend brand Z is less than 90%, a random sample of 100 doctors results in 83 who indicate that they recommend brand Z. The test statistic in this problem is approximately (round to the nearest hundredth):

-1.99

-2.33

2.33

-1.83

33. A local eat-in pizza restaurant wants to investigate the possibility of starting to deliver pizzas. The owner of the store has determined that home delivery will be successful if the average time spent on the deliveries does not exceed 34 minutes. The owner has randomly selected 23 customers and has delivered pizzas to their homes in order to test if the mean delivery time actually exceeds 34 minutes. Suppose the P-value for the test was found to be 0.0290. State the correct conclusion.

At = 0.03, we fail to reject H0.

At = 0.05, we fail to reject H0.

At = 0.02, we reject H0.

At = 0.025, we fail to reject H0.

34. If is computed to be 0.763, then the power of the test is

0.263.

0.237.

0.737.

0.763.

35. Approximately ____% of the area under the normal curve is between 2 and +2.

Group of answer choices

50

95

68

99.7

36. Professor Whata Guy surveyed a random sample of 420 statistics students. One of the questions was "Will you take another mathematics class?" The results showed that 252 of the students said yes. What is the sample proportion of students who say they will take another math class?

Group of answer choices

0.252

0.775

0.42

0.6

37. A national caterer determined that 87% of the people who sampled their food said that it was delicious. A random sample of 144 people is obtained from a population of 5000. The 144 people are asked to sample the caterer's food. Will the distribution of the sample proportion saying that the food is delicious, be approximately normal? Answer Yes or No.

38. A greenhouse in a tri-county area has kept track of its customers for the last several years and has determined that 28% of its customers plant a vegetable garden in the spring. The greenhouse obtains a random sample of 1000 of its customers. What is the mean of the sampling distribution of the sample proportion of customers that plant a vegetable garden in the spring?

0.28

0.002

0.72

2800

39. A simple random sample of size n = 1040 is obtained from a population whose size is N=1,200,000 and whose population proportion with a specified characteristic is p = 0.32. Describe the sampling distribution.

Approximately normal; p = 0.32, p = 0.1347

Exactly normal; p = 0.32, p = 0.1347

Approximately normal; p = 0.32, p = 0.014

Exactly normal; p = 0.32, p = 0.014