Question

Students recruited at the cafeteria at Hope College were blindly given a single Skittles® candy to put in their mouth. They were told the five possible flavors and then were asked which flavor they had. Of the 154 healthy students tested, 78 gave the correct answer. Of the 118 students tested who had stuffy or runny noses, 44 gave the correct answer.

1. Did the study involve random sampling, random assignment, both, or neither?

2. An appropriate analysis of the data shows that there is strong evidence that healthy students were more likely to give the correct answer. Is it appropriate to conclude that the health of the student affects ability to taste? Why or why not?

Answer 1

1. Study did not involve random sampling. They tested 154 healthy students and 118 unhealthy students (students who had stuffy or runny noses).

2. Let be the proportion of healthy students why gave correct answer and be the proportion of unhealthy students why gave correct answer.

The hypotheses are:

This is two tailed test.

The sample proportions are:

The pooled proportion is:

The test statistic is:

The p-value is:

Since p-value = 0.0278 < 0.05, reject null hypothesis.

We can conclude that the health of the student affects ability to taste.