On a nationwide test taken by high school students, the mean score was 54 and the standard deviation was 13. The scores were normally distributed. Complete the following statements.
(a) Approximately 68% of the students scored between_____and ________.
(b) Approximately (68%, 75%, 95%, 99.7% )of the students scored between 28 and 80.
+37158 Look at your bell curve one standard deviation above and one standard deviation below covers approx 68 %
54-13 = 41 54 + 13 = 67
so between 41 and 67 covers 68%
z score for 80 - z score for 28 =
80 is two SD 28 is - 2SD
.9772 - 0228 = .9544 = ~ ~ 95%
