Step-by-step explanation:
4x 3.5 + 4x 2.3
14 + 9.2
= 23.2
%change=100(572-650)/650= -12%
The sales decreased by 12%
The volume flow rate of the air being pumped into the football will be given by:
Q=V*A
Where
V=Speed
A=Area
You know that your pump expels air at speed of 8.2 ft/s
The area of The needle of your pump is
A=pi*r^2=pi*((4.5/1000)*(3.28))^2=0.00068442 ft^2
Finally
Q=V*A=(8.2 ft/s)*(0.00068442ft^2)=0.005612243 ft^3/s
14850 is the average profit
and 18000 is the charge of $40
so 18000-14850 is your answer