Answer:
$ 9,12
Explanation:
We first get the slope of the function;
Slope = change in credit/time
= (17.44 - 19.72 )/ (63 - 44)
= -2.28/19
= - 0.12 , its a negative slope indicating a decreasing function
To get remaining credit after 76 minutes of calls, we multiply time and slope;
= 0.12 × 76
= $ 9.12
Therefore, the remaining credit after 76 minutes will be $ 9.12