The SAT is an exam used by college and universities to evalu

The SAT is an exam used by college and universities to evaluate undergraduate applicants. The test scores are normally distributed. In a recent year, the mean test score was 1511 and the standard deviation was 315. The test scores of four students selected at random are 1931, 1332, 2230, and 1397. 1.Find the z score that corresponds to each value. 2.Determine whether any of the values are unusual. Give unusual value and very unusual value as needed.

Solution

for 1931:

Z = 1931 -1511 / 315 = 1.333

for 1332

z = 1332 - 1511/315 = -0.568

for 2230

z = 2230 -1511/315 = 2.2823

for 1397

z = 1397 - 1511 /315 = -0.3619

no, none of the values are unusual as they fall in the range of z -6 to 6