Python 3 floating point operations with loop

Question

I try to understand why the sequence of operations forward and backward produces different final results (293.02992793 vs 293.02992793000004)? Could you please help with the explanation?

cf = [100, 50, 40, 20, 30, 25]
rate  = 1.03
FV = 0
for i in range(len(cf)): 
    print(i,' ',FV)
    FV += cf[i] * rate**(len(cf)-i-1)       
print(FV)

FV = 0
i = len(cf) - 1
while i>=0:
    print(i,' ',FV)
    FV += cf[i] * rate**(len(cf)-i-1) 
    i = i-1
print(FV)

cf = cf[::-1]
FV = 0
for i in range(len(cf)): 
    print(i,' ',FV)
    FV += cf[i] * rate**(i)       
print(FV)

0 0

1 115.92740743

2 172.20284793000002

3 215.91192793000002

4 237.12992793

5 268.02992793

293.02992793

5 0

4 25.0

3 55.900000000000006

2 77.11800000000001

1 120.82708000000001

0 177.10252050000003

293.02992793000004

0 0

1 25.0

2 55.900000000000006

3 77.11800000000001

4 120.82708000000001

5 177.10252050000003

293.02992793000004