Question

A research study investigated differences between male and female students. Based on the study results, we can assume the population mean and standard deviation for the GPA of male students are µ = 3. 5 and Ď = 0. 5. Suppose a random sample of 100 male students is selected and the GPA for each student is calculated. Find the interval that contains 95. 44 percent of the sample means for male students.

Answer 1

Using the normal distribution and the central limit theorem, it is found that the interval that contains 99.44% of the sample means for male students is (3.4, 3.6).

In a normal distribution with mean $\mu$ and standard deviation $\sigma$, the z-score of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

• It measures how many standard deviations the measure is from the mean.  

• After finding the z-score, we look at the z-score table and find the p-value associated with this z-score, which is the percentile of X.

• By the Central Limit Theorem, the sampling distribution of sample means of size n has standard deviation $s = \frac{\sigma}{\sqrt{n}}$.

In this problem:

• The mean is of $\mu = 3.5$.

• The standard deviation is of $\sigma = 0.5$.

• Sample of 100, hence $n = 100, s = \frac{0.5}{\sqrt{100}} = 0.05$

The interval that contains 95.44% of the sample means for male students is between Z = -2 and Z = 2, as the subtraction of their p-values is 0.9544, hence:

Z = -2:

$Z = \frac{X - \mu}{\sigma}$

By the Central Limit Theorem

$Z = \frac{X - \mu}{s}$

$-2 = \frac{X - 3.5}{0.05}$

$X - 3.5 = -0.1$

$X = 3.4$

Z = 2:

$Z = \frac{X - \mu}{s}$

$2 = \frac{X - 3.5}{0.05}$

$X - 3.5 = 0.1$

$X = 3.6$

The interval that contains 99.44% of the sample means for male students is (3.4, 3.6).

You can learn more about the normal distribution and the central limit theorem at brainly.com/question/24663213