Formula to get increase by 80%

[Abdul]

Hi,

I have thefollowing
Y1 Y2 Y3 Y4
1000 1000 1000 1000
800 800 800
640 640
512
Total 1000 1800 2440 2952

the logic like this

Every year 1000 New Plus 80 % from previous year diminishing value

so Y3 figures are like this

1000 New
80 % of Y2 New =800
80 % of Y1 remaining (800)=640


Can I get this one through a formula

thanks




Y1 = 1000
Y2 = 1000 + 80 % of Y1
Y3 = 1000 + 80 % of Y2 base (1000) + 80 % of Y1 Remaining (800)
Year 1 Sales 1000
Year 2 Sales = 1000 + 80 % of year 1 (800)
Ples 80 % of year 1 =800
Total year 2 Sales = 1800

Year 3 Sales = 1000
Plus 80 % of year 2 base =800
Plus 80 % of year 1 balnce (80 % 0f 800)
Total Year 3 =
Year 3 Sales = 1000+ 80 % of Year 2 Addition (80% of 800) +
Y2 Sales 1000+ 80% of year 1 = 1000+ 800= 1800
Y3 Sales = 1000

 

[Sheeloo]

Try
=A1*(0.8)^B1
with 1000 in A1 and years in B1