Question

solve the third term of a Geometric progression is 9 and the fifth term is 16. find the fourth term

Answer 1

Answer:

let the 1st term is a

common ratio us r

3rd term=ar^(3-1)=ar^2

5th term=ar^(5-1)=ar^4

dividing,

ar^2/ar^4=9/16

=> 1/r^2=9/16

=> r^2=16/9

=> r=4/3

ar^2=9

=> a×4/3×4/3=9

=> a=9×9/16=81/16

4th term=ar^(4-1)

=81/16(.4/3)^3

=81×64/16×27

=3×4

=12

4th term is 12