Question

I really need help with this question. Can anyone please help me? I have been stuck on this problem for days now.

Answer 1

Yay, geometric sum
an=8(2)^(r-1)
anyway, sum of geometric sequence where a1=first term and n=which one and r=common ratio is
$S_n=\frac{a_1(1-r^n)}{1-r}$
so
first term is 50
common ratio is 2
n=8

$S_8=\frac{50(1-2^8)}{1-2}$
$S_8=\frac{50(1-256)}{-1}$
$S_8=-50(-255)$
S8=12760 visitors in first 8 weeks