Question

I need help with this practice problem from my ACT prep guide As I am completely new to this topic of math, please explain step-by-step as you solve on how you got your answer, and how to get the answer Thanks in advance!! There is no rush at all :)

Answer 1

14.5

Step 1:

Find the constant added which leads to the following term.

. Since 2 terms are given the 6th and the 10th term and they have a difference of 4 terms between:

a(6) + 4d = a(10)

with d representing the constant in question and n the terms position.

Step 2:

Find the required terms by starting from the known ones and adding or subtracting depending on their position.

. Since d = 1.25 and the 4rth term is 2 terms below the known 6th:

a(4) = a(6) - 2d

and keep the sequence until each of the first 4 terms are found.

Step 3:

Sum the first 4 terms found:

. a(1) + a(2) + a(3) + a(4) = Sum