Question

The first and last terms of a 52-term arithmetic series are listed in the table. What is the sum of the series?


Term Number Term
1 1
52 154

Answer 1

@ranga

Answer 2

Sum of an arithmetic series = N * (first term + last term) / 2

Answer 3

There are two formulas for the sum of an arithmetic series. In the previous problem we used the other formula. Here this formula is more appropriate.

Answer 4

\[s _{n}=n/2(a1+a_n)\]

Answer 5

Yes. Identify each variable in the formula and plug in the numbers from the problem.

Answer 6

a_1=1
a_n=52

Answer 7

Yes and what is n?

Answer 8

I don't know

Answer 9

a_1=1
a_n=154

n = 52

Answer 10

Look at the left column in the problem. The first term number is 1. The last term number is 52. So how many terms are there?

Answer 11

154

Answer 12

154 is the last term.
But it is the fifty-second term. That means there are 52 terms in the series. n = 52.

Answer 13

oh ok

Answer 14

i got 14300

Answer 15

Plug the numbers into the formula and calculate the sum.

Answer 16

Try again.

Answer 17

3900

Answer 18

Are you just reading off your various answer choices?

Answer 19

no im not

Answer 20

am i still wrong

Answer 21

sum = 52 / 2 * (1 + 154) = ?

Answer 22

52/2=26 1+154=155
26*155=4030

Answer 23

i was doing it in my head i know where i made my mistake

Answer 24

yes, 4030.

Answer 25

Thank you!

Answer 26

You are welcome.

Answer 27

This was correct! Tysm!