What is the value of r of the geometric series? Sigma-Summation Underscript n = 1 Overscript 3 EndScripts 1.3 (0.8) Superscript n minus 1
0.8
1.3
3.0
3.2

answer:

at time x=0 we have 1000, at time x=1 we have 2000, at time x=2 we have 4000.  

so that's an initial value of 1000 and a ratio of 2,

y = 1000 (2^x)

hope this !

answer is  

a.

5.56

hope you get this right.