Answer:
a) The probability of selling less than 100 gallons (x≤1) is P=0.16.
b) The mean number of gallons is M=80 gallons.
Step-by-step explanation:
The probability of selling x, in hundred of gallons, on any day during the summer is y(x)=0.32x, in a range for x from [0;2.5].
The probability of selling less than 100 gallons (x≤1) is then:

The mean number of gallons can be calculated as:

-3x + 7y = -16 . . . (1)
-9x + 5y = 16 . . . .(2)
(1) x 3 => -9x + 21y = -48 . . . (3)
(2) - (3) => -16y = 64 . . . (4)
Required equivalent system of equations is
-9x + 5y = 16
-16y = 64
Step-by-step explanation:
<u>Step 1: Cross Multiply</u>



<u>Step 2: Divide both sides by 4</u>


Answer: 
Maybe you should contact your teacher