Find the mean for the given set of data.
18, 15, 22, 18, 25, 19, 23
20

20

Step-by-step explanation:

You find the mean by adding up all the numbers in a data set, then dividing by the number added.

18 + 15 + 22 + 18 + 25 + 19 + 23 + 20 = 160

We added 8 numbers together, so we divide 160 by 8

160/8 = 20

hello from mrbilldoesmath!

answer:

a(n) - a(n-1) -3

discussion:

this ones a bit interesting. given a(n) = 5 - 3n consider this:

a(n-1) = 5 - 3(n-1)

          = (5 - 3n) + 3             => but a(n) = 5 - 3n, the first term

          = a(n)   + 3                 => subtract 3 from both sides

a(n-1) -3 = a(n)  

or

a(n) - a(n-1) -3

you,

mrb