Question

According to a recent article in the Wall Street Journal, 40% of web surfers who view online pop up ads remember them. Suppose a random sample of 5 web surfers is selected. What is the standard deviation in the number that will remember the ad

Answer 1

The value is
`\sigma = 1.0954`

Explanation:

From the question we are told that

The proportion of people that remember the ad is p = 0.40

The sample size is n = 5

Generally this study of number of web surfers who view online pop up ads and remember them follow binomial distribution in that the outcome is two (which either they remember them or not) , the number of trial is finite , each the two outcome is consistent throughout the study.

Generally the standard deviation in the number that will remember the ad is mathematically represented as

`\sigma = √(n * p * (1- p))`

=>
`\sigma = √( 5 * 0.40 * (1- 0.40))`

=>
`\sigma = 1.0954`