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

Answer:

Mean = 21.3

Standard Deviation = 2.48

Step-by-step 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

$\text{Standard deviation} = \sqrt{npq}\\=\sqrt{np(1-p)}\\=\sqrt{30\times 0.71\times (1-0.71)}\\=2.48$

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