Empirical Rule Practice Problems

See also: Solutions to Empirical Rule Practice Problems

1. What percent of a normal population is more than 2 standard deviations above the mean?
P( z > 2 ) =

2. What percent of adult women have heights between 65.5 and 68 in (5′5½″ and 5′8″)?
P( 65.5 ≤ x ≤ 68 ) =

3. What proportion of adult women have heights greater than 70.5 in (5′10½″)?
P( x > 70.5 ) =

4. What’s the probability that a randomly selected adult woman is less than 63 in tall (5′3″)?
P( x < 63 ) =

5. If a woman is 68 in (5′8″) tall, what’s her percentile rank?
P( x _____ 68 ) =

6. What’s the area under the curve between 58 in and 68 in (4′10″ and 5′8″)?
P( 58 < x < 68 ) =

7. What proportion of adult women are between 5′5½″ and 5′6½″?
P( 65.5 ≤ x ≤ 66.5 ) =