Question

he U.S. Bureau of Labor Statistics reports that the average annual expenditure on food and drink for all families is $5700. Assume that the annual expenditure on food and drink is normally distributed and that the standard deviation is $1500. What percentage of families spend more than $4000 annually on food and drink

Answer 1

87.08% percentage of families spend more than $4000 annually on food and drink

Explanation:

Given -

average annual expenditure on food and drink for all families is $5700

Mean
`(\\u)` = 5700

standard deviation
`(\sigma )` = 1500

Let X be the no of families spend annually on food and drink

percentage of families spend more than $4000 annually on food and drink =

`P(X > 4000)` =
`P((X - \\u )/(\sigma )> ( 4000 - 5700)/(1500))`

=
`P(Z > - 1.13)` Using
`(Z = (X - \\u )/(\sigma ))`

= 1 -
`P(Z <- 1.13)`

= 1 - .1292

= .8708

= 87.08%