SOLUTION: a population of 5,000 test scores are found to be normally distributed with a mean of 50 and a std. deviation of 10
what percentage of scores are between 30 and 65
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what percentage of scores are between 30 and 65
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Question 431046: a population of 5,000 test scores are found to be normally distributed with a mean of 50 and a std. deviation of 10
what percentage of scores are between 30 and 65 Answer by ewatrrr(24785) (Show Source):
Hi
*Note:
mean of 50 and a std. deviation of 10
z = -20/10 = -2 and z = 15/10 = 1.5
P(between 30 and 65) = P( -2 > z < 1.5) = .9332 - .0228 = .9104
91.04% of them are between 30 and 65
Area under the graph between z = -2 and z = 1.5
