In an Arlington, NY school, the heights of the population of girls are normally distributed with a mean of 63 inches and a standard deviation of 2 inches. If there are 450 girls in the school, determine how many of the girls are shorter than 60 inches. Round the answer to the nearest integer

Respuesta :

Answer:

Number of girls shorter than [tex]60[/tex] inches are [tex]301[/tex].

Step-by-step explanation:

Given: The heights of the population of girls in an Arlington, NY school follows a normal distribution.

Mean[tex]=63[/tex]

Standard deviation[tex]=2[/tex]

Total number of girls[tex]=450[/tex]

Now using the formula,

Standard normal variant, [tex]z=\frac{x-mean}{standard deviation}[/tex]

Now, substitute the values and replace [tex]x[/tex] by [tex]60[/tex]

So. [tex]z=\frac{60-63}{2}[/tex]

[tex]z=-\frac{3}{2}[/tex] or [tex]-1.5[/tex]

Now, probability of girls shorter than [tex]60[/tex] inches

[tex]p(z>-1.5)=0.668[/tex]              look up the value in the normal distribution table

Therefore, number of girls shorter than [tex]60[/tex] inches

[tex]=0.668[/tex]×[tex]450[/tex]

[tex]=301[/tex]