A typical adult has an average IQ score of 105 with a standard deviation of 20. If 20 randomly selec

A typical adult has an average IQ score of 105 with a standard deviation of 20. If 20 randomly selected adults are given an IQ test, what is the probability that the sample mean scores will be between 85 and 125 points?

For x = 125, our z-score and probability is seen here
Z = 1

P(x < 1) = 0.841345

For x = 85, our z-score and probability is seen here
Z = -1

P(x < -1) = 0.158655

So what we want is the probability between these values:<br />
0.841345 - 0.158655 = 0.68269