If a home goods retailer pays $$31\mathrm{.}50$ for the vacuum cleaner shown here, answer the following questions. $($Round dollars to the nearest cent and percents to the nearest tenth of a percent.$)$

An advertisement has a picture of a vacuum cleaner. From top to bottom, the text of the ad is as follows.

$12$ amp Powervac Plus

$$89\mathrm{.}99$

Microfiltration

On$-$board tools

$1$ year Product Replacement Policy, $$7\mathrm{.}99$

$($a$)$

What is the percent markup based on selling price?

$\%$

$($b$)$

If the retailer pays $$1\mathrm{.}20$ to the insurance company for each product replacement policy sold, what is the percent markup based on selling price of the vacuum cleaner and policy combination?

$\%$

$($c$)$

If $6,000$ vacuum cleaners are sold in a season and $40\%$ are sold with the insurance policy, how many additional "markup dollars," the gross margin, were made by offering the policy?

$

$($d$)$

As a housewares buyer for the retailer, what is your opinion of such insurance policies, considering their effect on the "profit picture" of the department? How can you sell more policies?