Answer:
Gavin would be expected to run during 36.5 miles during his 11th week of the training plan
Explanation:
In the first week of his running plan,the number of miles covered = 5 miles
Weekly mileage will increase by 3.5 miles every week.
At the end of second week, the number of miles covered = 5 + 3.5 = 8.5
At the end of third week, the number of miles covered = 8.5 + 3.5 = 12
The series is 5, 8.5, 12, ...
Consider this as an AP, where a = 5, d = 3.5
By formula,
![a_(n) = a + (n-1)d](https://img.qammunity.org/2021/formulas/mathematics/middle-school/j1u0egttnj5tdraj46hwzfhv1j7sd2yonb.png)
Substituting the values in the above equation, we get
![a_(11) = 5 + (10-1) 3.5](https://img.qammunity.org/2021/formulas/mathematics/middle-school/rpn05om92xzn8qivtu6si0m6m10arm824j.png)
= 5 +(9)3.5
= 5 + 31.5
=36.5 miles.
Gavin would be expected to run during 36.5 miles during his 11th week of the training plan