Question

@welshfella, this is the next problem

Answer 1

evaluate \[\sum_{n=3}^{12}20(0.5)^(n-1)\]

Answer 2

I know the the 20(0.5)^(n-1) would be100 but i'm not sure about the 12 and sigma sign again....

Answer 3

oh wait actually I think I got the answer 9.997 right???

Answer 4

100?

when n = 3 , 20(0.5)^(3-1) = 20 * 0.25 = 5

Answer 5

wait were are you getting the .25 from????

Answer 6

ohh well I got the 5 haha I don't know what I did wrong there probably plugged it in wrong but i'm still confused on were you got to .25 from..

Answer 7

0.5^2

Answer 8

0.5^(3-1) = 0.5^2

Answer 9

ohhh ok

Answer 10

i got 9.99 as the sum

Answer 11

i'm just adding it all up right now, give me like 10 seconds

Answer 12

did you round up? because i'm still getting 9.997

Answer 13

nevermind lol, can you help me with one more I promise it's the last one.