Answer
a) $E(2000)=460$ dollars
$E(15,000)=850$ dollars
b) The number of dollars Reynalda earned when she managed to sell 2000 and 15,000 dollars worth of goods in a week.
c) $E(0) =400$ Reynalda's salary when she didn't sell anything
d) Net change: +$390$ dollars
Avg. rate of change: $0.03$
e) 3%
Work Step by Step
a) $E(2000)=400+0.03 \cdot 2000=460$ dollars
$E(15,000)=400+0.03 \cdot 15000=850$ dollars
b) The answers represent the number of dollars Reynalda has earned (her total salary) when she managed to sell 2000 and 15,000 dollars worth of goods in a week.
c) $E(0) =400$ Since Reynalda didn't sell anything, she just earned her base weekly salary which is $400$ dollars.
d) Net change: $E(15,000)-E(2000)=850-460=+390$ dollars (the positive answers means that there is a profit)
Avg. rate of change: ${E(b)-E(a) \over b-a}={E(15,000)-E(2000) \over 15,000-2000}={850-460 \over 13000}=0.03$
e) The commission is based on the percentage of goods worth sold. That is the $0.03$ part of the function, but it is represented in decimal form. To represent a decimal as a percentage, just multiply it by 100: $0.03 \cdot 100 =3\%$
