Answer:
-1
Explanation:
We have that the mean (m) is equal to 66, the standard deviation (sd) 9
They ask us for P (x <57)
For this, the first thing is to calculate z, which is given by the following equation:
z = (x - m) / sd
We have all these values, replacing we have:
z = (57 - 66) / (9)
z = -1
57 score to z-score is -1