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# Students were given an exam

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Students were given an exam...

Students were given an exam with 300 multiple-choice questions. The distribution of the scores was normal and mean was 195 with a standard deviation of 30.

16. What were the scores of the students who were within one standard deviation of the mean?

17. What percent of students did that include?

18. What was the score of students who scored in the middle of the class? (50% did better, 50% did worse).

19. If A’s are given to students who score 90% or above, what is the minimum Z-score of someone getting an A?

20. Let’s say you got 235 on this test. Your colleague is in a different section of this course. Her score was 82 out of 100 on her test. In her section the mean was 72 and the standard deviation was 7. Which one of you did better? (Hint: compare Z-scores.)

Submitted: 6 years ago.Category: Homework
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10/3/2011
Tutor: Curtis K, Engineer replied 6 years ago
Curtis K, Engineer
Category: Homework
Satisfied Customers: 1,453
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Hi there,

16. scores = 195 ± 30
scores = 165 to 225
17. percent = 68.27%

18. 195

19. 1.2816

20. your z score = (235-195)/30 = 40/30
=1.333
colleague z score = (82-72)/7 =1.428
Your colleague is doing better because she has a higher z score.

Curtis K, Engineer
Category: Homework
Satisfied Customers: 1,453
Experience: Computer Engineer with MBA; Many years of math tutoring experience;
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Customer reply replied 6 years ago

Can you explain how you solved #19. I'm not sure how this payment thing works. I deposited \$30 and my acct. says 0 now, so I'm assuming I paid you 30?

Tutor: Curtis K, Engineer replied 6 years ago
Would you like to ask this question?
Customer reply replied 6 years ago
Am I supposed to pay you another \$30 for this answer?
Tutor: Curtis K, Engineer replied 6 years ago

No, since you already paid for the original post.

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