Assume that 75 was the mean test score on an exam, with a standard deviation of 4 points. What percent had scores between 67 and 75? U

Question

Assume that 75 was the mean test score on an exam, with a standard deviation of 4 points.
What percent had scores between 67 and 75? Use the % symbol in your answer.

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RobertKer 3 years 2021-08-25T05:58:57+00:00 1 Answers 1 views 0

Answers ( )

  1. Philomena
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    2021-08-25T06:00:31+00:00
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    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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