Question 1

A researcher wants to test whether the average number of hours college students sleep per night is less than 7 hours. Which of the following correctly states the null and alternative hypotheses?

Accepted Answer

$$H_0$$: \mu = 7$$; H_a$$: \mu \u003c 7$$

Question 2

A city claims that at least 60% of its residents support a new recycling program. You collect a random sample and find that only 55% support it. Which test should you use to evaluate the city's claim?

Accepted Answer

1-PropZTest

Question 3

Which of the following best describes the p-value in hypothesis testing?

Accepted Answer

The probability of observing your sample results (or more extreme) if the null hypothesis is true.

Question 4

You conduct a hypothesis test with $$\alpha = 0.05$$ and obtain a p-value of $$0.03. $$What is the correct conclusion?

Accepted Answer

Reject $$H_0$$; there is enough evidence to support $$H_a.$$

Question 5

A 95% confidence interval for the mean weight of a new candy bar is $$[4.8, 5.2]$$ ounces. The company claims the mean weight is 5.5 ounces. What can you conclude?

Accepted Answer

There is evidence the company's claim is false.

Question 6

Which test statistic is appropriate for comparing the average test scores between two independent classes?

Accepted Answer

2-SampleTTest

Question 7

If a confidence interval for the difference between two population means contains zero, what does this imply?

Accepted Answer

The two population means may be the same.

Question 8

A medical researcher tests whether a new drug increases recovery rates compared to the standard treatment. The data is categorical (recovered/not recovered). Which test should be used?

Accepted Answer

2-PropZTest

Question 9

Which of the following is NOT a correct interpretation of a 95% confidence interval for a population mean?

Accepted Answer

There is a 95% probability that the sample mean is within the interval.

Question 10

A student wants to test if the average number of TV episodes watched per week is different from 10. Which alternative hypothesis should be used?

Accepted Answer

$$H_a: \mu 
eq 10$$

Question 11

Which parameter is estimated when using a 1-PropZTest?

Accepted Answer

Population proportion ($$p)$$

Question 12

A school claims that the average SAT score of its students is at least 1200. You collect a sample and find a mean of 1150. Which test should you use?

Accepted Answer

T-Test

Question 13

Which of the following statements about the null hypothesis ($$H_0) is $$correct?

Accepted Answer

$$H_0$$ always contains an equality sign ($$=).$$

Question 14

A 95% confidence interval for the difference in average commute times between two cities is $$[-2, 4]$$ minutes. What does this interval suggest?

Accepted Answer

There may be no difference in average commute times between the two cities.

Question 15

Which of the following is the correct formula for a confidence interval for a population mean when the population standard deviation is unknown?

Accepted Answer

$$\bar{x} \pm t^* \frac{s}{\sqrt{n}}$$

Question 16

A p-value is calculated as $$0.08$$ for a test with $$\alpha = 0.05. $$What is the correct decision?

Accepted Answer

Fail to reject $$H_0$$; there is not enough evidence to support $$H_a.$$

Question 17

Which of the following is a real-world example where a 2-PropZTest would be appropriate?

Accepted Answer

Comparing the proportion of smokers in two different cities.

Question 18

Which of the following is NOT a step in the problem-solving checklist for hypothesis testing?

Accepted Answer

Accept the null hypothesis if the p-value is greater than $$\alpha.$$

Question 19

A researcher wants to estimate the average number of hours spent studying per week by college students. Which technology function should they use to find a confidence interval?

Accepted Answer

T-Interval

Statistical Inference, Hypothesis Testing, and Confidence Intervals: Study Guide

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