Question

The ages of people who attend a local church are normally distributed . The mean age is 39.5 , and the standard deviation is 18. First sketch a normal curve. Then find the probability that that a person chosen at random from this church is ages 21.5 or younger

Answer 1

Given:

The ages of people who attend a local church are normally distributed.

The mean age = μ = 39.5

And the standard deviation = σ = 18

The sketch of the normal curve will be as follows:

As shown the peak of the curve at the mean value = 39.5

and the distance between the consecutive numbers = 18

now, we will find the probability that a person chosen at random from this church is ages 21.5 or younger

So, we will find P( x < 21.5)

As shown, from the graph:

The answer will be = 0.1587