A oncepopular childrens doll is slowly declining in populari

A once-popular children\'s doll is slowly declining in popularity. The quartic function f(x) = - 0.022x^4 + 0.457 x^3 - 2.492 x^2 - 5.279x + 87.419, where x is the number of years since 1993, can be used to estimate the number of dolls of this type that were sold (in thousands) during a given year from 1993 to 2003. Estimate how many dolls were sold in 1998. The number of dolls sold in 1998 was approximately Square (Round to the nearest thousand.)

Solution

f(x) = -0.022x^4 +0.475x^3 -2.492x^2 -5.279x +87.419

the number years from 1993 to 1998 is \'5\'
so f(5) = -0.022(5)^4 +0.475(5)^3 -2.492(5)^2 -5.279(5) +87.419
f(5) = -13.75 +59.375 -62.3 -26.395 +87.419
f(5)= 146.794 - 102.445
f(5) =44.4
number of dolls sold in 1998 was = 44