Question

A national survey showed that 44% of college students drink. A professor provided his own survey by choosing a random sample of 244 students and found that 96 of them drink. Is this an unusual result contradicting the national survey or it is in line with it? Answer the question by determining how far away the proportion is from 44% in terms of standard deviations.

Answer 1

It is an unusual result contradicting the national survey.

Explanation:

National survey showed 44% of college students who drink.

The professor's survey showed that 96/244 = 39% drink.

The professor's survey deviated from the national survey is 5% (44% - 39%) representing about 0.25% (5% squared) variance.

Standard deviation is the spread of a set of numbers from their mean. In other words, it measures how far an observed value is from the mean. It can be calculated by getting the square root of the variance.