he diameters of red delicious apples of an orchard have a normal distribution with a mean of 3 inches and a standard deviation of 0.5 inch. One apple will be randomly chosen. What is the probability of picking an apple with diameter between 2.5 and 4.25 inches?

Respuesta :

Answer: 0.8351

Step-by-step explanation:

Given :Mean : [tex]\mu=\text{ 3 inches}[/tex]

Standard deviation : [tex]\sigma =\text{ 0.5 inch}[/tex]

The formula for z -score :

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

For x= 2.5 ,

[tex]z=\dfrac{2.5-3}{0.5}=-1[/tex]

For x= 4.25 ,

[tex]z=\dfrac{4.25-3}{0.5}=2.5[/tex]

The p-value = [tex]P(-1<z<2.5)=P(z<2.5)-P(z<-1)[/tex]

[tex]=0.9937903-0.1586553=0.835135\approx0.8351[/tex]

Hence,  the probability of picking an apple with diameter between 2.5 and 4.25 inches =0.8351.