For a few years, the SAT consisted of three components: writing, critical reading, and mathematics. Let W
Question:
For a few years, the SAT consisted of three components: writing, critical reading, and mathematics. Let W = SAT Writing score and X = SAT Critical Reading score for a randomly selected student. According to the College Board, in 2012 W had mean 488 and standard deviation 114, while X had mean 496 and standard deviation
114. Suppose X and W have a bivariate normal distribution with Corr(X, W) = .5.
a. An English department plans to use X + W, a student’s total score on the nonmath sections of the SAT, to help determine admission. Determine the distribution of X + W.
b. Calculate P(X + W > 1200).
c. Suppose the English department wishes to admit only those students who score in the top 10% on this Critical Reading + Writing criterion. What combined score separates the top 10% of students from the rest?
Step by Step Answer:
Modern Mathematical Statistics With Applications
ISBN: 9783030551551
3rd Edition
Authors: Jay L. Devore, Kenneth N. Berk, Matthew A. Carlton