Question

Assume that adults have IQ scores that are normally distributed with a mean of mu equals 100 and a standard deviation sigma equals 15. Find the probability that a randomly selected adult has an IQ less than 130.

Answer 1

Answer:

The probability would be 97.8%

Step-by-step explanation:

In order to find that, lets look at the amount of standard deviations away the amount given is. Since the number is 30 away from the mean, and the standard deviation is 15, we can find the total number of deviations it is away.

30/15 = 2

Now that we have that, we can look at the probability curve for standard deviations. Outside of 2 standard deviations above is only a 2.2% likelihood. Since that is the case, we can find the amount that would be under that as 100% minus the amount we just found.

100% - 2.2% = 97.8%