Question

A university interested in tracking its honors program believes that the proportion of graduates with a GPA of 3.00 or below is less than 0.16. In a sample of 200 graduates, 24 students have a GPA of 3.00 or below. The value of the test statistic and its associated p-value at the 5% significance level are _________, respectively.

Answer 1

Answer:

The value of the test statistic and its associated p-value at the 5% significance level are -1.54 and 0.9382, respectively.

Step-by-step explanation:

A university interested in tracking its honors program believes that the proportion of graduates with a GPA of 3.00 or below is less than 0.16.

This means that the null hypothesis is:

$H_{0}: p \geq 0.16$

Testing this hypothesis, means that the alternate hypothesis is:

$H_{a}: p > 0.16$

The test statistic is:

$z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}$

In which X is the sample mean, $\mu$ is the value tested at the null hypothesis, $\sigma$ is the standard deviation and n is the size of the sample.

0.16 is tested at the null hypothesis:

This means that $\mu = 0.16, \sigma = \sqrt{0.16*0.84}$

In a sample of 200 graduates, 24 students have a GPA of 3.00 or below.

This means that $n = 200, X = \frac{24}{200} = 0.12$

Value of the test statistic:

$z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}$

$z = \frac{0.12 - 0.16}{\frac{\sqrt{0.16*0.84}}{\sqrt{200}}}$

$z = -1.54$

Pvalue:

The pvalue is the probability of finding a sample mean above 0.12, which is 1 subtracted by the pvalue of z = -1.54.

Looking at the z-table, z = -1.54 has a pvalue of 0.0618

1 - 0.0618 = 0.9382

The value of the test statistic and its associated p-value at the 5% significance level are -1.54 and 0.9382, respectively.