Data Science Analysis 4

Question 1

In hypothesis testing, what does a p-value of 0.03 mean at the 0.05 significance level?

Accepted Answer

Reject the null hypothesis

Answer

A p-value below the significance threshold of 0.05 leads to rejecting the null hypothesis.

Question 2

What does a 95% confidence interval for a mean represent?

Accepted Answer

A range that would contain the true mean in 95% of repeated samples

Answer

The confidence level reflects how often the interval would capture the true parameter over repeated sampling.

Question 3

A Type I error in hypothesis testing is:

Accepted Answer

Rejecting a true null hypothesis (false positive)

Answer

A Type I error wrongly rejects a null that is actually true, a false positive.

Question 4

Increasing the sample size generally has what effect on the standard error of the mean?

Accepted Answer

It decreases

Answer

Standard error shrinks proportionally to 1 over the square root of the sample size.

Question 5

Which test compares the means of two independent groups?

Accepted Answer

Independent samples t-test

Answer

The independent samples t-test evaluates whether two group means differ significantly.

Data Science Practice Test