A researcher is examining whether the amount of time newborns can sleep without being disturbed is related to parental stress. The researcher asked 30 parents to report the longest amount of time in number of minutes their newborn child has been able to sleep without waking up. Then the parents were asked to rate their stress levels.
What is the critical value assuming α = .05?
A) .367
B) .361
C) .463
D) .471

Question

Quizplus · Accepted Answer

Since the sample size is small (n = 30), we need to use a t-distribution to calculate the critical value. With a 2-tailed test and α = .05, the degrees of freedom are (n-1) = 29. Using a t-table, the critical value is approximately ±2.045. However, this can be approximated to ±2.0 for simplicity.

The correct critical value option is not given in the answer choices, so we need to choose the closest option. The closest option is B, which is .361. However, this is not the correct critical value, so we need to choose the next closest option. The next closest option is A, which is .367. This is approximately equal to the correct critical value of ±2.0. Therefore, the correct answer is A.

A Researcher Is Examining Whether the Amount of Time Newborns