SOLUTION: A placement exam for entrance into a math class yields a mean of 80 and a standard deviation of 10. The distribution of the scores is roughly bell-shaped. Use the Empirical Rule to
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Question 69160This question is from textbook Elementary Statistics
: A placement exam for entrance into a math class yields a mean of 80 and a standard deviation of 10. The distribution of the scores is roughly bell-shaped. Use the Empirical Rule to find the percentage of scores that lie between 60 and 80. This question is from textbook Elementary Statistics
You can put this solution on YOUR website! A placement exam for entrance into a math class yields a mean of 80 and a standard deviation of 10. The distribution of the scores is roughly bell-shaped. Use the Empirical Rule to find the percentage of scores that lie between 60 and 80.
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60 is 2 standard deviations below the mean.
The emperical rule says there is approximately 90% of normally distributed
data within 2 standard deviations of the mean. Your interval is half of
that because it is the data between the mean and two standard deviations
below the mean. Your answer is 47.5%.
Cheers,
Stan H.
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