Z-Test and T-Test MCQs

What is the main assumption required to perform a z-test?

• Unknown population variance

• Small sample size

• Known population variance

• Paired samples

What sample size is generally considered sufficient for a z-test?

• Less than 20

• 25

• 30 or more

• More than 100

Which of the following is NOT a type of z-test?

• One-sample z-test

• Two-sample z-test

• Paired z-test

• Chi-square test

A one-sample z-test is used when:

• Comparing two related samples

• Comparing two population proportions

• Comparing a sample mean to a known population mean

• Standard deviation is unknown

Which of the following distributions does the z-statistic follow?

• Binomial

• Poisson

• Normal

• Exponential

When is a paired z-test considered appropriate?

• Never

• When sample size is large and differences are normally distributed

• When samples are independent

• When population variances are unknown

What kind of data is required for a parametric test like the z-test or t-test?

• Nominal or ordinal

• Interval or ratio

• Binary

• Categorical

Which test should be used when the sample size is small and standard deviation is unknown?

• Z-test

• Chi-square test

• T-test

• ANOVA

A two-sample z-test compares:

• A sample to a population

• A population to another population

• Two independent sample means

• Two proportions

In a z-test, if the p-value is less than alpha (α), you:

• Accept the null hypothesis

• Fail to reject the null hypothesis

• Reject the null hypothesis

• Stop the test