Suppose the grades in a statistics class follow a normal distribution with a mean of 75 and a standard deviation of 8. What is the z-score for a grade of 85?

Step 1 ：Step 1: To find the z-score, we need to use the formula \( Z = \frac{X - \mu}{\sigma} \), where \( X \) is the value we are interested in, \( \mu \) is the mean, and \( \sigma \) is the standard deviation.

Step 2 ：Step 2: Substituting the given values into the formula, we get \( Z = \frac{85 - 75}{8} \).

Step 3 ：Step 3: Simplify the expression to get the z-score.