The function f left parenthesis x right parenthesis equals StartFraction 90 Over 1 plus 270 e Superscript negative 0.122 x EndFractionf(x)=

90

1+270e0.122x models the percentage, f(x), of people x years old with a certain disease.Use this function and a calculator with an e Superscript xex key to evaluate f left parenthesis 77 right parenthesisf(77) and describe what this answer means in practical terms.

f(7777)almost equalsnothing% (Round to one decimal place.)

In practical terms, this means the following.

About nothing% of nothing-year-olds have the disease.