Answer
The median income decreases 7082.26 dollars from 50 to 60 years of age.
Work Step by Step
$x=50$:
$ŷ=-55961.675+4314.374\times50-45.66\times50^2=45607.025$
$x=60$:
$ŷ=-55961.675+4314.374\times60-45.66\times60^2=38524.765$
$38524.765-45607.025=-7082.26$
