Question

Assume the resting heart rates for a sample of individuals are normally distributed with a mean of 85 and a standard deviation of 5.

Use the​ 68-95-99.7 rule to find the following quantities.

a. The relative frequency of rates less than 95 using the​ 68-95-99.7 rule is nothing.

​(Round to three decimal places as​ needed.)

b. The relative frequency of rates greater than 90 using the​ 68-95-99.7 rule is nothing.

​(Round to three decimal places as​ needed.)

c. The relative frequency of rates between 75 and 85 using the​ 68-95-99.7 rule is nothing.

​(Round to three decimal places as​ needed.)

Answer 1

Given that ,

mean = = 85

standard deviation = = 5

a)

By using empirical rule,

P( Less 95 ) = P( less   + 2 )

= 68% + 13.5% + 2.35% + 0.15%

= 84.0 %

= 0.840

b)

P( Above 90 ) = P( Above + )

= 13.5% + 2.35% + 0.15%

= 16.0%

= 0.160

c)

P( Between 75 and 85 once ) = P( Between 85 - 10 and 85 )

= 13.5% + 34%

= 47.5 %

= 0.475