Your interest formula is given to you.
<span>Interest in a year = principal (the amount invested) * rate (the interest rate) * period (the time you're measuring) </span>
<span>Interest = 55,000 * 2% * 1 year = 55,000 * 0.02 * 1 = $1,100 </span>
<span>How much would you need to have made for your spending power to keep with inflation? Your interest rate would have needed to match the inflation rate, otherwise, prices are going up faster than you're saving. </span>
<span>Required interest = 55,000 * 3.24% * 1 year = 55,000 * 0.0324 * 1 = $1,782 </span>
<span>How much buying power did you lose? The difference between your required interest and your actual interest. </span>
<span>Buying power lost = 1,782 - 1,100 = $682. You lost this much in buying power. </span>
Answer: 37
Step-by-step explanation:
Given : Significance level : 
Critical value : 
margin of error : E= 1 mile per gallon
Population standard deviation:
miles per gallon.
We know that when the population standard deviation is known then the formula to find the sample size is given by :

[Round to the next whole number.]
Hence, the required number of automobiles should be used in the test = 37
APR refers to annual interest rate i e 4.5%
Difference:-
Now
Interest:-
Total savings:-
Remember the code:-
- Question's calculations mostly given in its options
I think it's 1/4 that's my answer