Question

Suppose the ages of multiple birth (3 or more babies) are normally distributed with a mean age of 31.7 years and a standard deviation of 5.2 years. What percent of these mothers are between the ages 30-35

Answer 1

The percent of these mothers are between the ages 30-35 is 36.53%

Explanation:

we are given

mean of age =31.7 years

`\mu=31.7`

standard deviation of 5.2 years

`\sigma=5.2`

For age=30 years:

x=30

we can find z-score

`z=(x-\mu)/(\sigma)`

we can plug values

`z=(30-31.7)/(5.2)`

`z=-0.32692`

For age=35 years:

x=35

we can find z-score

`z=(x-\mu)/(\sigma)`

we can plug values

`z=(35-31.7)/(5.2)`

`z=0.63462`

now, we can use normal distribution table

`P(-0.32692<z<0.63462)=0.3653`

now, we can find percentage

`=0.3653* 100`

=36.53%