Answer: $122.19
Explanation:
Hi, to answer this, first we have to calculate the additional KB that Astrid used:
KB used- KB limit=
6,978-5,000 = 1,978
Then, the cost of the plan is equal to a fixed fee (49) plus the product of the number of additional KB over 5,000(x) and the cost per KB (0.037).
Cost = 49+ 0.037 x
Substituting x =1,978
C = 49+ 0.037 (1,978)
C =49+73.186
C=$122.19
Feel free to ask for more if needed or if you did not understand something.