The relationship between the groceries index and the cost of living index. How do the indexes help you identify the best and worst cities in the list regarding cost if$100$ is the highest.

Atlanta: groceries index $85\mathrm{.}4$ cost of living index $78\mathrm{.}5$

Boston: groceries $96\mathrm{.}5$ cost of living index $85$

Charlotte: groceries index $83\mathrm{.}9$ cost of living index $74\mathrm{.}4$

Chicago : groceries index $90\mathrm{.}2$ cost of living index $80\mathrm{.}1$

Philadelphia: groceries index $84$ cost of living index $71\mathrm{.}9$

Raleigh: groceries index $80\mathrm{.}7$ cost of living index $75\mathrm{.}7$