Question

Assume the resting heart rates for a sample of individuals are normally distributed with a mean of 75 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 85 using the 68-95-99.7 rule is _____.

Answer 1

99.8 %

Explanation:

μ = 75 and σ = 5

The information about 68-95-99.7 rule is:

μ ± 0,5σ 68.3 % of all values will be in the interval

[ μ - 0,5σ ; μ + 0,5σ ] [ 72.5 : 77,5 ]

μ ± 1σ 95 % of all values will be in the interval

[ μ - 1σ ; μ + 1σ ] [ 70 : 80 ]

And:

μ ± 1,5σ 99.7 % of all values will be in the interval

[ μ - 1.5σ ; μ + 1.5σ ] [ 67,5 : 82,5 ]

And still 85 is bigger than 82,5 we can conclude that approximately 99.8 % will be smaller than 85 and then "the relative frecuency of rates less than 85 is very high 99.8 %