Question

A researcher collects a simple random sample of​ grade-point averages of statistics​ students, and she calculates the mean of this sample.

Under what conditions can that sample mean be treated as a value from a population having a normal​ distribution? Select all that apply.

A. The sample has more than 30 grade-point averages.
B. If the population of grade-point averages has a normal distribution.
C. The researcher collects more than 30 samples.
D. If the population of statistics students has a normal distribution.

Answer 1

A) The sample has more than 30​ grade-point averages.

B) If the population of​ grade-point averages has a normal distribution.

Explanation:

A normal distribution is a continuous probability function which describes and defines how sample are distributed within a given population, a normal distribution has also been described as a Gaussian distribution.

Random samples are samples obtained from a sampling procedures that has a non zero probability of been selected and a random sample is a sample whose selection is based on chance.