Stats Final Exam 3rd Qtr 2025

What kind of hypothesis test would you use?

1. A random sample of 49 medical doctors in LA showed that they worked an average of 53.1 hours/week with a standard deviation of 7.2 hours/week. If the California average is 60 hours/week, does this give evidence that the LA doctors work  significantly less than the rest of California?

• 1 Proportion z test

• 1 sample t test

• 1 sample z test

• None of these

Select the correct null and alternate hypothesis

1. A random sample of 49 medical doctors in LA showed that they worked an average of 53.1 hours/week with a standard deviation of 7.2 hours/week. If the California average is 60 hours/week, does this give evidence that the LA doctors work  significantly less than the rest of California?

• Ho: p = 60

  Ha: p < 60

• Ho: μ = 53.1

  Ha : μ < 53.1

• None of these

USA Today reported that in 1992, 39% of all elementary school children claimed that when they grow up they want to  do something to help other people. However, in 1995, 128 of a random sample of 317 of these same children claimed  that when they grow up they want to do something to help other people. Does this information indicate that the  proportion has increased? Suppose α = 0.05.

• 1 Proportion z test

• 1 sample t test

• 1 sample z test

• 1 Proportion z interval

Choose the correct set of hypothesis

USA Today reported that in 1992, 39% of all elementary school children claimed that when they grow up they want to  do something to help other people. However, in 1995, 128 of a random sample of 317 of these same children claimed  that when they grow up they want to do something to help other people. Does this information indicate that the  proportion has increased? Suppose α = 0.05.

• Ho: p = .39

  Ha : p > .39

• Ho: p = .40

  Ha : p > .40

• Ho: μ = .39

  Ha : μ > .39

• Ho: μ = .40

  Ha : μ > .40

What kind of hypothesis test would you use?

A psychologist claims that the mean age at which children start walking is 12.5 months. The following data give the age  at which 18 randomly selected children started walking.  

15 11 13 14 15 12 15 10 16 17 14 16 13 15 15 14 11 13 

Test at the 1% level of significance if the mean age at which children start walking is different from 12.5.

• 1 Proportion z test

• 1 sample t test

• 1 sample z test

• 1 sample t interval

Which would be equivalent to the hypothesis test in the previous question?

A psychologist claims that the mean age at which children start walking is 12.5 months. The following data give the age  at which 18 randomly selected children started walking.  

15 11 13 14 15 12 15 10 16 17 14 16 13 15 15 14 11 13 

Test at the 1% level of significance if the mean age at which children start walking is different from 12.5.

• A 90% confidence interval with 𝛂=.10

• A 99.5% confidence interval with 𝛂=0.005

• A 99% confidence interval with 𝛂=.01

• No confidence interval would be appropriate here.

What kind of hypothesis test would you use?

The population standard deviation for waiting times to be seated at a restaurant is known to be 10 minutes. An  expensive restaurant claims that the average waiting time for dinner is approximately 1 hour, but we suspect that this  claim is inflated to make the restaurant appear more exclusive and successful. A random sample of 30 customers yielded  a sample average waiting time of 50 minutes. Is there evidence to say that the restaurant’s claim is too high? 

• 1 Proportion z test

• 1 sample t test

• 1 sample z test

• 1 sample z interval

What kind of hypothesis test would you use?

5. In a survey of 1273 adults, 52% said it is not morally wrong to change the genetic makeup of human cells. What test would be indicated to address the following statement: “The majority of adults do not think it is morally wrong to  change the genetic makeup of human cells”

• 1 Proportion z test

• 1 sample t test

• 1 sample z test

• 1 sample z interval

Choose the correct set of hypothesis for this question

5. In a survey of 1273 adults, 52% said it is not morally wrong to change the genetic makeup of human cells. What test would be indicated to address the following statement: “The majority of adults do not think it is morally wrong to  change the genetic makeup of human cells”

• Ho: μ = .50

  Ha: μ > .50

• Ho: phat = .52

  Ha: phat > .52

• Ho: p = .52

  Ha: p > .52

Which is not a condition for the previous test?

5. In a survey of 1273 adults, 52% said it is not morally wrong to change the genetic makeup of human cells. What test would be indicated to address the following statement: “The majority of adults do not think it is morally wrong to  change the genetic makeup of human cells”

• np≥10

• SRS

• n≥30

• at least 12,730 adults in the population