Question

The value of the 4th term is 80. the sequence is being doubled each step what is the 7th term?

Answer 1

This is a geometric sequence with common ratio (r) = 2.
an = ar^(n - 1)
a4 = a(2)^(4 - 1) = a(2)^3 = 8a
8a = 80
a = 80/8 = 10

7th term (a7) = 10(2)^(7 - 1) = 10(2^6) = 10(64) = 640