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3 years ago

Assume that 75 was the mean test score on an exam, with a standard deviation of 4 points.

Mathematics

1 answer:

Tems11 [23]3 years ago

5 0

Answer:

68%

Step-by-step explanation:

The Empirical Rule states that, for a normally distributed random variable:

Approximately 68% of the measures are within 1 standard deviation of the mean.

Approximately 95% of the measures are within 2 standard deviations of the mean.

Approximately 99.7% of the measures are within 3 standard deviations of the mean.

In this problem, we have that:

Mean of 75, standard deviation of 4.

What percent had scores between 67 and 75?

67 = 71 - 4

75 = 71 + 4

Within 1 standard deviation of the mean, so, by the Empirical Rule, 68%.

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