$1-$The Western Company presents the production and cost data for the first six months of the $2020.$

MONTH UNITS TOTAL COST $($$$)$

$\backslash$table$[[$January$,25,000,60,000],[$February$,18,000,52,000],[$March$,13,000,42,000],[$April$,26,000,61,500],[$May$,30,000,67,500],[$June$,22,000,66,000]]$

Based on the given information and by using the high$-$low method, answer the following questions.

Determine the change level of units produced.

Determine the change level of the total costs.

Compute the variable cost per unit $($b$)$

Compute the total fixed cost $($a$).$

Determine the expected total cost if a total of $35,500$ units are produced in July.