T test

What is the FIRST step in hypothesis testing?

• Collect data

• Set alpha level

• State the null and alternative hypotheses

• Compute test statistics

A researcher wants to test whether a sample mean differs from a known population mean. Which hypotheses are correct?

• H0: μ₁ = μ₂ ; H1: μ₁ ≠ μ₂

• H0: μ = value ; H1: μ ≠ value

• H0: μ(d) = 0 ; H1: μ(d) ≠ 0

• H0: μ ≠ value ; H1: μ = value

Which of the following best describes a paired-samples t-test?

• Compares two independent groups

• Compares one sample to a known value

• Compares the same participants across two conditions

• Compares more than two groups

A study compares stress levels between nurses working day shift and night shift. Which test is most appropriate

• One-sample t-test

• Paired-samples t-test

• Independent-samples t-test

• Correlation

What does the alpha level (α) represent?

• Probability that the null hypothesis is true

• Probability of making a Type I error

• Probability of making a Type II error

• The p-value of the test

If α = 0.05 and p = 0.03, what should the researcher do?

• Fail to reject the null hypothesis

• Accept the null hypothesis

• Reject the null hypothesis

• Increase sample size

A p-value of 0.02 means:

• There is a 2% chance the null hypothesis is true

• There is a 98% chance the alternative is true

• If the null hypothesis is true, results this extreme or more extreme would occur 2% of the time

• If the null hypothesis is true, results this extreme occur 2% of the time

A researcher measures participants before and after a treatment. Which design is this?

• Between-subjects design

• Correlational design

• Within-subject design

• Cross-sectional design

A study reports: t(30) = 2.10, p = 0.041, α = 0.05. What is the correct conclusion?

• Fail to reject H0

• Reject H0

• Accept H0

• Cannot determine

Why is a within-subject design often preferred?

• It increases sample size

• It reduces variability by comparing participants to themselves

• It eliminates the need for hypothesis testing

• It Increases variability by comparing participants to themselves