Answer
A) "In June, the local stock car racing team used $1,290$ gallons of motor oil."
B) $g(7)=15.2$
Work Step by Step
A) Since the value of $t$ in $g(t)$ indicates how many months past March the motor oil is used, the value $3$ in $g(3)$ indicates $3$ months past March, or June. Since $g(t)$ is in one hundred gallons, the value $12.90$ corresponds to $1,290$ gallons. Piece this together and you get the statement "In June, the local stock car racing team used $1,290$ gallons of motor oil."
B) Since October is 7 months after March, the function will be represented by $g(7)$. Also, since the value for motor oil is in one hundred gallons, the value $1,520$ corresponds to $15.2$. Piece this together and you get $g(7)=15.2$.