speakbox produces cd$\text{'}$s for $15$$ per unit. The contribution margin ratio is $30\%.$ Fixed expenses total $27,000$$

a$)$calculate variable cost per unit

b$)$calculate the CD$\text{'}$s the company needs to sell to break even

c$)$how many sales the company needs to generate to earn a target operating incomebefore taxes of:

$10,800$$$.$ Assume income tax rate of $40\%$

d$)$assume the company expected to sell $10,000$ cds$,$ what is the margin of safety ratio? Explain as a percentage

e$)$assume the company expected to sell $10,000$ cds$,$ what is the margin of safety leverage? Explain as a percentage

f$)$using operating leverage if sales increase by $20\%$ of the expected sales, how much will operating income increase by$?$