Significance Tests and Decision Making

What is the purpose of hypothesis testing in statistics?

• To prove that a hypothesis is true beyond any doubt

• To make decisions based on data from a sample

• To calculate the mean of a dataset

• To graphically represent data

In hypothesis testing, what is the significance level (alpha) typically used?

• 0.1

• 0.05

• 0.5

• 1.0

How can the risk of committing a Type I error be reduced?

• Increase the significance level (alpha)

• Decrease the significance level (alpha)

• Increase the sample size

• Decrease the sample size

A procedure using a sample statistic to make a decision about the validity of a claim.

• Significance Level

• Significance Test

• Confidence Interval

• Confidence Level

When conducting a significance test for the difference in proportions, why do we pool the data when finding standard error?

• Because we like to swim

• Because we assume p1 = p2 in Ho

• Because the sample sizes are always equal

• To be safe and make sure we don't underestimate the standard error

• Because we don't the standard deviation.

A level of significance of 5% means:

• There's a 5% chance we're wrong

• There's a 5% chance we'll be wrong if we fail to reject the null hypothesis

• There's a 5% chance we'll be wrong if we reject the null hypothesis.

• There's a 5% chance you're right

In hypothesis testing, if the p-value is greater than the significance level (alpha), what is the appropriate decision?

• Reject the null hypothesis.

• Provide evidence for the alternative hypothesis.

• Fail to reject the null hypothesis.

• Increase the sample size and retest.

A fixed value used as a cutoff on what probability is or is not statistically significant.

• Significance Level

• Significance Test

• Confidence Interval

• Confidence Level

To reduce the probability of committing a Type II error, we should ___________.

• Increase the significance level (α).

• Decrease the significance level (α).

• Increase the P-value.

• Decrease the sample size.

A significance test was performed to test the null hypothesis H₀ : p = 0.5 versus the alternative H_a: p > 0.5. The test statistic is z = 1.40. Which of the following is closest to the P-value for this test?

• 0.0808

• 0.1492

• 0.1616

• 0.2984

• 0.9192