Starbucks Coffee classifies its customers into two types $$ unsatisfied or satisfied. The behavior of these customers can be summarized as follows:

Behavioral Metric $$ Unsatisfied Customer vs Satisfied Customer

Number of visits per month $2\mathrm{.}7$ vs $4\mathrm{.}3$

Average ticket size$/$visit $$3\mathrm{.}88$ vs $$5\mathrm{.}06$

Expected customer life $($years$)3\mathrm{.}3$ vs $4\mathrm{.}4$

$($a$)(4$ pts$)$ What is the difference in retention rate between two customer types? Show work. If the given information is not enough, what additional information would you need?

$($b$)(4$ pts$)$ What specific additional information would you need to determine the difference in customer lifetime value $($CLV$)$ between the average unsatisfied customer and the average satisfied customer?