A recent survey found that 63% of all adults over 50 wear glasses for driving. In a random sample of 100 adults over 50, what is the mean and standard deviation of those that wear glasses?
A)mean: 63; standard deviation: 4.83
B)mean: 63; standard deviation: 7.94
C)mean: 37; standard deviation: 4.83
D)mean: 37; standard deviation: 7.94

Question

Quizplus · Accepted Answer

The mean of those that wear glasses is found by multiplying the percentage (63%) by the sample size (100), giving 63. The standard deviation is calculated using the formula for the standard deviation of a binomial distribution, $\sqrt{n \cdot p \cdot (1-p)}$, where $n$ is the sample size (100) and $p$ is the probability (0.63), resulting in $\sqrt{100 \cdot 0.63 \cdot (1-0.63)} = \sqrt{23.31} \approx 4.83$.

A Recent Survey Found That 63% of All Adults Over