If the meanand the standard deviationof a continuous random variablethat is normally distributed are 20 and 5, respectively, find an interval that contains 68% of the distribution.

A. (18,24)

B. (15,25)

C. (12,25)

D. (10,30)

2. If the mean and the standard deviation of a continuous random variable that is normally distributed are 28 and 3 respectively, find an interval that contains 95% of the distribution.

A. (22,34)

B. (25,31)

C. (20,35)

D. (19,37)

3 A competency test has scores with a mean of 80 and a standard deviation of 10. A histogramof the datashows that the distribution is normal. Use the Empirical Rule to find the percentage of scores between 70 and 90.

A. 99.7%

B. 95%

C. 68%

D. 50%

4. The heights of adult women are normally distributed with a mean of 62.5 inches and standard deviation of 2.5 inches. Use the Empirical Rule to determine between what two heights 68% of adult women will fail.

A. (52.5,72.5)

B. (55,70)

C. (57.5,67.5)

D. (60,65)

5. The heights of adult women are normally distributed with a mean of 62.5 inches and standard deviation of 2.5 inches. Use the Empirical Rule to determine between what two heights 99.7% of adult women will fail.

A. (52.5,72.5)

B. (55,70)

C. (57.5,67.5)

D. (60, 65)

The solution provides answers to multiple choice questions on Empirical Rule of normal distribution. Relevant workings are also included.