the distribution of heights of adult men is approximately normal with mean 69 inches and standard deviation 2.5 inches. what percent of all men are -- to the nearest inch -- between 66.5 and 71.5 inches tall?



Answer :

Qwdog

The percentage of all men between 66.5 inches and 71.5 inches is 99.99%

The mean of the heights of adult men in inches = 69

The standard deviation of the adult men in inches = 2.5

The percentage of all men between the heights of 66.5 inches and 71.5 inches can be calculated using the normal distribution.

                           P(66.5 < x < 71.5)

First, let us find the standard form for these random samples using the formula,

                                 Z = (X - μ) / σ

where Z is the standard form

           X is the random sample

           μ is the mean

           σ is the standard deviation.

For x = 66.5,

                           z =  (66.5 - 69) / 2.5

                              = -2.5 / 2.5

                             = -1

For x = 71.5,

                          z = (71.5 - 69) / 2.5

                             = 2.5 / 2.5

                             = 1

The standardized form of those random samples are

              P(66.5 < x < 71.5) = P( -1 < z < 1)

which can be written as

                              = P(-1 < z < 0) + P(0 < z < 1)

By using the z-table we can find the value of z

                 P(-1 < z < 1) = 0.15866 + 0.8413

                                    = 0.99996

Then, the percentage of heights between 66.5 and 71.5 is

                                     = 0.99996 x 100

                                     = 99.99 %

                 

Learn more about the normal distribution in

https://brainly.com/question/13759327

#SPJ4