Assume that the heights of females in a certain village are normally distributed with a mean of 69 in. and standard deviation of 33 in. What percent of these females are between 6060 in. and 78 in.​ tall?

Respuesta :

Answer: 21.28%

Step-by-step explanation:

Given : Mean height of females = [tex]\mu=69\text{ in.}[/tex]

Standard deviation : [tex]\sigma=33\text{ in.}[/tex]

Let X be a random variable that represents the heights of females in village .

We assume that that the heights of females in a certain village are normally distributed .

Z-score : [tex]z=\dfrac{x-\mu}{\sigma}[/tex]

For x = 60 in.

[tex]z=\dfrac{60-69}{33}\approx-0.27[/tex]

For x = 78 in.

[tex]z=\dfrac{78-69}{33}\approx0.27[/tex]

Now by using standard normal distribution table , the probability that females are between 60 in. and 78 in.​ tall :-

[tex]P(60<x<78)=P(-0.27<z<0.27)\\\\=P(z<0.27)-P(z<-0.27)\\\\=0.6064198-0.3935801=0.2128397\approx0.2128=21.28\%[/tex]

Hence, the percent of these females are between 60 in. and 78 in.​ tall =21.28%