+389 What is the mean of the terms in the arithmetic sequence 13, 29, 45, ..., 141, 157?
+128475 There are [157 - 13] / 16 + 1 = 9 + 1 = 10 terms in the sequence
The mean will be the average of the middle two terms...so we have...
[(13 + 4*16) + (13 + 5*16)] / 2 = 85
[Notice that we could have found the same result by adding the first and last terms and dividing by 2 ]
+128475 There are [157 - 13] / 16 + 1 = 9 + 1 = 10 terms in the sequence
The mean will be the average of the middle two terms...so we have...
[(13 + 4*16) + (13 + 5*16)] / 2 = 85
[Notice that we could have found the same result by adding the first and last terms and dividing by 2 ]
