June 14, 2021 10:36 am
Topic starter
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The mean score on a certain test is 80. If the test scores have a normal distribution and the standard deviation is 7, what percent of examinees score between 66 and 94?
A) 50%
B) 68%
C) 82%
D) 96%
E) 98%
1 Answer
0
June 14, 2021 10:37 am
Topic starter
The range from 66 to 94 represents 14 points above and below the average. If the standard deviation is 7, then 14 points represents two standard deviations. Two standard deviations in each direction is 14+34+34+14=96% of all examinees.