Explanation

To find the sum of a consecutive series, multiply the number of terms in the list by the average value of the list.

To find the average value of a list, take the average of the largest and smallest values.

To find the number of terms on the list, add one to the range of the list. Thus, the sum of the series is .

To find the average value of a list, take the average of the largest and smallest values.

To find the number of terms on the list, add one to the range of the list. Thus, the sum of the series is .