$10-28$ Estimating a cost function, high$-$low method. Lacy Dallas is examining customer$-$service costs in the southern region of Camilla Products. Camilla Products has more than $200$ separate electrical products that are sold with a $6-$month guarantee of full repair or replacement with a new product. When a product is returned by a customer, a service report is prepared. This service report includes details of the problem and the time and cost of resolving the problem. Weekly data for the most recent $8-$week period are as follows:

$\backslash$table$[[$Week$,$Customer$-$Service Department Costs,Number of Service Reports$],[1,$$$13,300,185],[2,20,500,285],[3,12,000,120],[4,18,500,360],[5,14,900,275],[6,21,600,440],[7,16,500,350],[8,21,300,315]]$

Plot the relationship between customer$-$service costs and number of service reports. Is the relationship economically plausible?