Normal curve percent: practice

Psychology. Try each one, then open the answer. The Credit Sprint app generates unlimited new versions.

Item 1.

Scores are normally distributed with a mean of 500 and a standard deviation of 5. About what percent of scores fall between 490 and 510?

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These scores are within 2 standard deviations of the mean, which includes about 95% of a normal distribution.

Item 2.

Scores are normally distributed with a mean of 100 and a standard deviation of 10. About what percent of scores fall between 80 and 120?

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These scores are within 2 standard deviations of the mean, which includes about 95% of a normal distribution.

Item 3.

Scores are normally distributed with a mean of 50 and a standard deviation of 5. About what percent of scores fall between 45 and 55?

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These scores are within 1 standard deviation of the mean, which includes about 68% of a normal distribution.

Item 4.

Scores are normally distributed with a mean of 500 and a standard deviation of 5. About what percent of scores fall between 495 and 505?

Show answer

These scores are within 1 standard deviation of the mean, which includes about 68% of a normal distribution.

Item 5.

Scores are normally distributed with a mean of 500 and a standard deviation of 15. About what percent of scores fall between 470 and 530?

Show answer

These scores are within 2 standard deviations of the mean, which includes about 95% of a normal distribution.

Item 6.

Scores are normally distributed with a mean of 100 and a standard deviation of 10. About what percent of scores fall between 90 and 110?

Show answer

These scores are within 1 standard deviation of the mean, which includes about 68% of a normal distribution.