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vitfil [10]
3 years ago
11

The scores of 1000 students on a standardized test were normally distributed with a mean of 50 and a standard deviation of 5. wh

at is the expected number of students who had scores greater than 60?
Mathematics
1 answer:
blondinia [14]3 years ago
8 0

Answer:

23 students expected to have scores greater than 60.

Step-by-step explanation:

60 is 2 standard deviations above the mean.  This translates into a z-score of +2.  According to a table of z-scores, the area under the standard normal curve to the left of z = 2 is 0.9772; that to the right of z = 2 is 1.0000 - 0.9772, or 0.0228.  This 0.0228 represents the probability that a given score is greater than 60.

This fraction (0.0228) of 1000 students comes out to 23 (rounded up from 22.75).

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