Calculate variable cost per unit, contribution margin ratio, and increase in fixed costs

In 2022, Wiggins Ltd had a break-even point of $350000 based on a selling price of $7 per unit and fixed costs of $105000. In 2023, the selling price and the variable cost per unit did not change, but the break-even point increased to $455000

Required:

a. Calculate the variable cost per unit and the contribution margin ratio for 2022

b. Calculate the increase in fixed costs for 2023