To lease the car then purchase at the end of the five$-$year lease. The purchase price is $$19,894.$ The sales tax rate is $15\%.$ The interest rate for leasing the car is $7\mathrm{.}49\%.$ The monthly lease payment, including the sales tax, is $$324\mathrm{.}70.$ The residual value of the vehicle at the end of the lease term is $$8,296\mathrm{.}85.$ Initial amount due at signing: First monthly payment. Based on the information above, calculate the following; a$).$Initial payment due at signing. b$).$ Total of all monthly payments. c$).$ Residual cost at conclusion of lease. This is what you pay if you decide to purchase the vehicle, so it will include sales tax. d$).$ Total cost if you lease then purchase at the end of the five$-$year lease.