statistics

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If the grades on a police entrance exam are normally distributed with a mean of 100 and a standard deviation of 15, what percentage of students received grades of less than 115?

  • statistics -

    Use z-scores.

    z = (x - mean)/sd

    x = 115
    mean = 100
    sd = 15

    Use a z-table to find probability of less than 115 using the z-score calculated above. Convert to a percent.

    I hope this will help.

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