Answer:
a) 18%
b) if Frank and Sarah are unsure about future inflation rate, they can agree on a variable interest rate. For e.g. this year the inflation rate was 17%, so the interest charged is 18%. If next year the interest rate is 15%, then the interest charged should be 16%.
the formula that they can use to calculate inflation rate is:
- for calculating the first year's inflation rate = [(CPI₁ - CPI₀) / CPI₀] x 100
- for calculating the second year's inflation rate = [(CPI₂ - CPI₁) / CPI₁] x 100
Step-by-step explanation:
principal $1,000
real return = 1%, that means that Frank will earn inflation rate + 1%
since the CPI increases by 17% every year, then Frank must charge 17% + 1% = 18%