1.In many schools across the country the 8^th grade students have to take a math assessment to see what level of math they should start in high school. The range of these scores is from 400- 1000 points. Suppose we know that the average on these math scores (mean) is 650, with a standard deviation of 75, which forms a normal distribution.

a.Student A got a 725 on the test. What is the Z score of the score of 725? And please interpret the Z score. Please elaborate calculation procedures. (Hint: by interpreting the Z score, please tell the number of standard deviation is above/below the mean) (4 points)

b.What proportion (percentage) of students scored between 725 and the mean score? Please elaborate calculation procedures. (4 points)