contestada

Lunch break: In a recent survey of 600 working Americans ages 25-34, the average weekly amount spent on lunch as S45.32 with standard deviation S2.87. The weekly amounts are approximately bell-shaped. Part 1 out of 3 Estimate the percentage of amounts that were less than S42.45. Round the answer to one decimal place. Approximately _______% of the amounts were less than $42.45.

Respuesta :

Answer:

Step-by-step explanation:

given that in a recent survey of 600 working Americans ages 25-34, the average weekly amount spent on lunch as S45.32 with standard deviation S2.87.

The weekly amounts are approximately bell-shaped

so for practical purposes we assume X =  ages of working Americans is N(45.32, 2.87)

Estimate the percentage of amounts that were less than S42.45

First let us find probability

P(X<42.45) = F(42.45)

= [tex]P(Z<\frac{42.45-45.32}{2.87} \\=P(Z<-1)[/tex]

= 0.5-0.3413

=0.1687

So 16.87% of the amounts were less than 42.45 dollars