The standard deviation is 1, I believe...
compound interest equation for annually compounded
A=final amount
P=principal
r=rate in decimal
t=time in years
given that
A=1550
P=1000
r=5.5%=0.055
find t
divide both sides by 1000
take ln of both sides
use ln rule
divide both sides by ln(1.055)
using a calculator, we get that t=8.18544 yrs
so about 8.2yrs
The first one should be -24
2 is d there is no reason for those numbers to be negative
3=B
I think that the answer is quadratic