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Chapter 6:The Normal Random Variable 9. The MATH SAT Scores for all students who

ID: 3054198 • Letter: C

Question

Chapter 6:The Normal Random Variable 9. The MATH SAT Scores for all students who applied to the School of Engineering are normally distributed with ?-629 and ? 60. The School of Engineering has decided to accept those students whose scores fall within the top 15%. What is the minimum score an applicant must have in order to be accepted into the Engineering School? 10. The average length of time required for students to complete a test in an Introductory Statistics course is found to be 50 minutes with a standard deviation of 12 minutes. If students are allowed 80 minutes to complete the test, approximately what percentage of the students will have sufficient time to complete the test? (Assume that the time required to complete the test followsa normal distribution.) 11. The daily sales at the campus bookstore throughout the school year have a probability distribution that is approximately normal with ?-$1530 and ?-$120. The bookstore must have at least $1200 in sales per day to break even. What is the probability that on a given day the bookstore will not break even?

Explanation / Answer

9. Mu = 629
Sigma = 60
Let the scored asked be c.

P(X>=c) = .15

So, (c-629)/60 = 1.0364

c = 60*1.0364+629 = 691.184

So, min score for top 15% is 691.184