Year Cash Flow

$0$$ $8,400$

$13,000$

$22,200$

$35,000$

a$.$ What is the profitability index for the cash flows if the relevant discount rate is $6$ percent?

b$.$ What is the profitability index for the cash flows if the relevant discount rate is $17$ percent?

c$.$ What is the profitability index for the cash flows if the relevant discount rate is $21$ percent?