If 0.3 = 1 then 0.9 = 3 because 0.3+0.3+0.3=the 3.
CD = certificate of deposit (an investment)
Interest rate, i = 10% per annum (simple interest)
Principal, P = $2000 (present value)
Period, T = 3 months = 0.25 year
Simple interest formula
Interest earned = Pit
=2000*0.10*0.25
=$50
Balance at maturity (amount that investor gets after three months)
=$2000+$50
=$2050
Answer: 12
Step-by-step explanation:
The formula to find the sample size is given by:-
, where 
is the population standard deviation, 
is the z-value for the 
confidence interval and E is the margin of error .
As per given , we have
Population standard deviation : 
z-value for 95% confidence interval : 
Margin of error : E= 3
Then, the required minimum sample :-
Hence, the required minimum sample size = 12
