In Table 5.1 with Exercise 5.30, we see that scores on the Writing portion of the SAT (Scholastic Aptitude Test) exam are normally distributed with mean 492 and standard deviation 111. Use the normal distribution to answer the following questions:
(a) What is the estimated percentile for a student who scores 450 on Writing?
(b) What is the approximate score for a student who is at the 90th percentile for Writing?

Table 5.1

Exercise 5.30

The Scholastic Aptitude Test (SAT) was taken by 1,547,990 college-bound students in the class of 2010. The test has three parts: Critical Reading, Mathematics, and Writing. Scores on all three parts range from 200 to 800. The means, standard deviations, and shapes for the three tests are shown in Table 5.1. Draw a sketch of the normal distribution for the scores on Critical Reading and a sketch of the normal distribution for the scores on Writing. Label at least 3 points on the horizontal axis in each case.

Transcribed Image Text:

Mean St.Dev. Shape 112 Approximately normal 116 Small left skew Approximately normal Critical Reading 501 Mathematics Writing 516 492 111