Assume that from 1930 to 1980 , the number of deaths from lead poisoning (per 100,000 people) decreased dramatically and could be modeled by $\mathrm { f } ( \mathrm { x } ) = - 0.0148 \mathrm { x } ^ { 2 } + 54.2 \mathrm { x } - 49,200$, where $\mathrm { x }$ is the year. Determine when, to the nearest year, this death rate was 150 or less by graphing $\mathrm { y } = \mathrm { f } ( \mathrm { x } )$ and $\mathrm { y } = 150$ in $[ 1930,1980,10 ]$ by $[ 0,200$, 25 ].
A) 1960 or after
B) 1973 or after
C) 1964 or after
D) 1967 or after

Question

Quizplus · Accepted Answer

The function $ f(x) $ represents a quadratic equation, and by graphing it along with $ y = 150 $, we find that the death rate was 150 or less starting in 1967.

Assume That from 1930 to 1980 , the Number of Deaths