You are the accounting manager for Kool Ragz, Inc., a manufacturer of men's and women's clothing. The company needs to borrow $$1,900,000$ for $90$ days in order to purchase a large quantity of material at "closeout" prices. The interest rate for such loans at your bank, Rimrock Bank, is $15\%$ using ordinary interest.$($a$)$What is the amount $($in $$)$ of interest on this loan?$ $($b$)$After making a few "shopping" calls, you find that Southside National Bank will lend at $15\%$ using exact interest. What is the amount $($in $$)$ of interest on this offer? $($Round your answer to two decimal places.$)$$ $($c$)$So that it can keep your business, Rimrock Bank has offered a loan at $14\mathrm{.}5\%$ using ordinary interest. What is the amount $($in $$)$ of interest on this offer?$ $($d$)($Challenge$)$ If Southside National wants to compete with Rimrock's last offer $($part c$)$ by charging $$1,875$ less interest, what rate $($as a $\%),$ rounded to the nearest hundredths of a percent, must it quote using exact interest? $\%$