Scores on a test have a mean of 66 and a standard deviation of 9. Michelle has a score of 57. Convert Michelle's score to z-score

-1

Step-by-step 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