Question

recent survey found that 71​% of all adults over 50 wear glasses for driving. In a random sample of 30 adults over​ 50, what is the mean and standard deviation of those that wear​ glasses? Round the answers to the nearest hundredth.

Answer 1

Mean = 21.3

Standard Deviation = 2.48

Explanation:

We are given the following in the question:

p = 71​% = 0.71

Sample size, n = 30

We have to find the mean and the standard deviation of those that wear​ glasses.

`\text{Mean} = np\\=30(0.71)\\=21.3`

Thus, the mean of those who wear glasses is 21.3

`\text{Standard deviation} = √(npq)\\=√(np(1-p))\\=√(30* 0.71* (1-0.71))\\=2.48`

Thus, the standard deviation of those who wear glasses is 2.48