How do you solve this problem

Math 112 Chapter 6 Placement Scores The histogram below displays the placement exam scores for 213 students entering a Computer Science degree program. The mean exam score is 10.221 with a standard deviation of 3.859. 35 30 25 20 15 10 Number of Students Placement Score (a) Find the placement exam score that is one standard deviation below the mean and the placement exam score that is one standard deviation above the mean. (b) What percent of the 213 students scored within one standard deviation of the mean? (Hint: Count how many students scored between the two values you computed in (a) and divide by 213?) (c) Find the placement exam score that corresponds to two standard deviation below the mean and the one that corresponds to two standard deviations above the mean. What percentage of the student scored within two standard deviation of the mean? (d) Find the placement exam scores that correspond to three standard deviations below and above the mean. What percent of the students scored within three standard deviations of the mean