Question

how do i use the geometric sequence formula to figure out what the 6th term is (after 11)?

15
14
13
12
11

Answer 1

\[a_n=a_1r ^{n-1} \] this formula

Answer 2

First you need to find r, the common ratio do you know how to find this?

Answer 3

is this geometric

Answer 4

yes

Answer 5

would i find the ratio by dividing each one?

Answer 6

14/15=.93333333 13/14=.92857.... you should get the same number if it's geometric. You divide a term by the previous one

Answer 7

ok, so do i round it off to .93 for all of them? what do i do then?

Answer 8

I'm not sure this is geometric but if it were you would simply use your formula that
says that for any term a_n, in this case the 6th term is when n=6, you multiply the first
term a1 by the common ratio r to the power of n-1=6-1=5
So
a_6=15*(r)^5

Answer 9

thanks!!

Answer 10

i did 15*9.3^5 and got this weird number. 1043532.554

Answer 11

you get a number like 10.435.... because you have r=.93 not 9.3 i still don't think you have a geometric here you seem to have an arithmetic sequence so your next term is 10.

Answer 12

it´s supposed to be a geometric sequence.

Answer 13

How about for this geometric sequence: 15,13,11,9,7 ? i got a weird answer

Answer 14

@marybel86