A check$-$cashing store is in the business of making personal loans to walk$-$up customers.

The store makes only one$-$week loans at $7\mathrm{.}9$ percent interest per week.

a$.$ What APR must the store report to its customers? What EAR are customers actually

paying? $($Do not round intermediate calculations and enter your answers as a

percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16.)$

b$.$ Now suppose the store makes one$-$week loans at $7\mathrm{.}9$ percent discount interest per

week. What's the APR now? The EAR? $($Do not round intermediate calculations and

enter your answers as a percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16.)$

c$.$ The check$-$cashing store also makes one$-$month add$-$on interest loans at $7\mathrm{.}9$ percent

discount interest per week. Thus if you borrow $$220$ for one month $($four weeks$),$ the

interest will be $($$$220{1\mathrm{.}079}^4)-$$$220=$$$78\mathrm{.}20.$ Because this is discount interest,

your net loan proceeds today will be $$141\mathrm{.}80.$ You must then repay the store $$220$ at

the end of the month. To help you out, though, the store lets you pay off this $$220$ in

installments of $$55$ per week. What is the APR of this loan? What is the EAR? $($Do not

round intermediate calculations and enter your answers as a percent rounded to $2$

decimal places, e$.$g$.,32\mathrm{.}16.)$