Exploring Two-Tailed Z-Test for Mean

What was the mean age of college students in city X in recent years before the current study?

• 22 years

• 24 years

• 23.8 years

• 23 years

What type of hypothesis test is appropriate when the population standard deviation is known?

• chi-square test

• z-test

• t-test

• ANOVA

At what z-score values do we reject the null hypothesis in a two-tailed test at a 5% significance level?

• ±1.64

• ±1.96

• ±2.58

• ±2.33

What was the calculated test statistic for the sample mean age of 23.8?

• 1.64

• 2.33

• 1.96

• 2.16

What conclusion is drawn when the test statistic is greater than the critical value at a 5% significance level?

• Cannot conclude anything

• Fail to reject the null hypothesis

• Need more data

• Reject the null hypothesis

What is the new significance level when testing at a stricter criterion in the tutorial?

• 0.01

• 0.05

• 0.1

• 0.02

What critical z-score corresponds to a 2% significance level in a two-tailed test?

• ±2.33

• ±1.96

• ±1.64

• ±2.58

What happens to the null hypothesis when the test statistic is less than the critical value at a 2% level?

• It is considered false

• It is considered true

• It is not rejected

• It is rejected

What does a test statistic of 2.16 imply about the mean age at a 2% significance level?

• It is more than 23

• It is less than 23

• It has not changed

• It has changed

What is the conclusion of the hypothesis test at a 2% significance level?

• Results are inconclusive

• Sufficient evidence to support change

• Not enough evidence to support change

• Further testing is needed