Answer:
a. 9.1 percent deflation between the first and second years, and 4 percent deflation between the second and third years.
Step-by-step explanation:
To calculate the rate of inflation/deflation, we have to divide by the oldest price index.
The second year, the variation of the price index was:
![\Delta PI/PI=(PI_2-PI_1)/(PI_1)=(100-110)/(110)=(-10)/(110)=-0.909=-9.1\%](https://img.qammunity.org/2020/formulas/business/college/flos7frt2upnf946gcn1sjt1i3854kuriw.png)
This means a 9.1% deflation.
The third year, the variation of the price index was:
![\Delta PI/PI=(PI_3-PI_2)/(PI_2)=(96-100)/(100)=(-4)/(100)=-0.04=-4\%](https://img.qammunity.org/2020/formulas/business/college/s96o00b2s4ux1cwumyk94nju3ro0fombiq.png)
This means a 4% deflation.