Find the indicated mean.
-Find the mean of the 7th through the 57th terms inclusive of the sequence an = 2n + 58.
A) 244
B) 72
C) 172
D) 122

Question

Quizplus · Accepted Answer

The mean of a sequence can be found by averaging the first and last terms of the subset of the sequence you're interested in. For the sequence $a_n = 2n + 58$, the 7th term is $a_7 = 2(7) + 58 = 72$ and the 57th term is $a_{57} = 2(57) + 58 = 172$. The mean of these two terms is $\frac{72 + 172}{2} = \frac{244}{2} = 122$.

Find the Indicated Mean