Quiz: Chapter 9 Review Quiz Time Limit: 01:30:00 Submit Quiz This Question: 1 pt
ID: 3320045 • Letter: Q
Question
Quiz: Chapter 9 Review Quiz Time Limit: 01:30:00 Submit Quiz This Question: 1 pt 6 of 11 (5 complete) This Quiz: 11 pts possibl The distribution of the scores on a certain exam is N(50,5), which means that the exam scores are Normally distributed with a mean of 50 and standard deviation of 5 a. Sketch the curve and label, on the x-axis, the position of the mean, the mean plus or minus one standard deviation, the mean plus or minus two standard deviations, and the mean plus or minus three standard deviations b. Find the probability that a randomly selected score will be greater than 60. Shade the region under the Normal curve whose area corresponds to this probability O A. 35 40 45 50 55 60 65 3c -20 -o + +20+30 45 50 55 60 65 70 75 30-20 -o + +20 +30 35 45 47.5 50 52.5 55 65 3c-20 -o + +20+30 b. What is the probability that a randomly selected score will be greater than 60? greater than 60 is about % Using the Empirical Rule, the probability that a randomly selected score will Type an integer or a decimal.)Explanation / Answer
Solution:-
a) option A.
b) P(X > 60) = P(Z > (60 - 50)/5)
= P(Z > 2)
= 1 P(Z < 2)
= 1 0.9772
= 0.0228
= 2.28%
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