Question 1

Which of the following best describes a Type I error in hypothesis testing?

Accepted Answer

Rejecting the null hypothesis when it is actually true.

Question 2

In the context of hypothesis testing, what does the p-value represent?

Accepted Answer

The probability of observing data as extreme as the sample, assuming the null hypothesis is true.

Question 3

A manufacturer claims that 20% of cars of a certain model need costly transmission work. After a redesign, which of the following is the correct null hypothesis?

Accepted Answer

$$H_0$$: p = 0.20$$

Question 4

If a hypothesis test fails to reject the null hypothesis, which statement is most accurate?

Accepted Answer

There is insufficient evidence to reject the null hypothesis.

Question 5

Which of the following is a correct interpretation of a p-value of 0.023 in a study comparing two reading programs?

Accepted Answer

If the null hypothesis is true, there is a 2.3% chance of observing a difference as large or larger than what was found.

Question 6

Which of the following best describes the relationship between confidence intervals and hypothesis tests?

Accepted Answer

A confidence interval can be used to approximate a two-sided hypothesis test.

Question 7

What is the effect of increasing the sample size in a hypothesis test?

Accepted Answer

It decreases the probability of a Type II error.

Question 8

Which of the following statements about alpha levels ($$\alpha) is $$TRUE?

Accepted Answer

The alpha level is the threshold for deciding whether a p-value is statistically significant.

Question 9

A test of $$H_0$$: p = 0.7$$ vs H_A$$: p \u003c 0.7$$ fails to reject the null hypothesis. Later it is discovered that p = 0.6$. What type of error has been made?

Accepted Answer

Type II error

Question 10

Which of the following increases the power of a hypothesis test?

Accepted Answer

Increasing the sample size

Question 11

If the p-value is greater than the chosen alpha level ($$\alpha$$), what should you conclude?

Accepted Answer

Fail to reject the null hypothesis.

Question 12

Which of the following is a common misconception about p-values?

Accepted Answer

The p-value is the probability that the null hypothesis is true.

Question 13

A company wants to know if the percentage of employees willing to pay for on-site day care has changed from last year's 45%. Which alternative hypothesis is appropriate?

Accepted Answer

$$H_A: p 
eq 0.45$$

Question 14

Which of the following best describes the effect size in hypothesis testing?

Accepted Answer

The difference between the observed statistic and the null hypothesis value.

Question 15

Which of the following is TRUE about statistical significance?

Accepted Answer

Statistical significance means the p-value is less than the alpha level.

Question 16

In a criminal trial analogy for hypothesis testing, what does 'innocent until proven guilty' represent?

Accepted Answer

The null hypothesis

Question 17

Which of the following is NOT a recommended practice when reporting results of a hypothesis test?

Accepted Answer

Interpreting the p-value as the probability that the null hypothesis is true.

Question 18

If a test of $$H_0$$: p = 0.5$$ vs H_A$$: p 
eq 0.5$$ rejects the null hypothesis and later it is discovered that p = 0.65$, what type of error has been made?

Accepted Answer

No error

Question 19

Which of the following is TRUE about the power of a hypothesis test?

Accepted Answer

Power is the probability of correctly rejecting a false null hypothesis.

Question 20

Which of the following would increase the probability of a Type I error?

Accepted Answer

Increasing the alpha level ($$\alpha)$$

Hypothesis Testing for Proportions: Concepts, Errors, and Significance

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