DSST Statistics 3

Question 1

A researcher wants to estimate the average height of students at a university. She randomly selects 50 students. This is an example of:

Accepted Answer

Simple random sampling

Answer

Randomly selecting individuals from the population without structured grouping is simple random sampling.

Question 2

The standard error of the mean is equal to:

Accepted Answer

σ / √n

Answer

Standard error = σ / √n; it measures how much sample means vary around the population mean.

Question 3

Which of the following best describes a negatively skewed distribution?

Accepted Answer

The tail extends to the left

Answer

A negatively skewed distribution has a longer tail on the left side, pulling the mean below the median.

Question 4

In a chi-square test of independence, the null hypothesis states that:

Accepted Answer

The two variables are independent

Answer

The null hypothesis in a chi-square test of independence is that the two categorical variables are not associated.

Question 5

What does a 95% confidence interval mean?

Accepted Answer

If repeated sampling were done, 95% of such intervals would contain the true parameter

Answer

The correct frequentist interpretation is that 95% of confidence intervals constructed this way will capture the true parameter.

DSST - DANTES Subject Standardized Tests Practice Test