# 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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