if the fixed cost for the Job Shop were changed to $305,000, what would the new break-even point in numbers of units

The question you have provided is missing important information needed for the calculation of break even point.

However step by step approach for the calculation of the break even point is given below :

Understand what break even point is :

Break even point is the level of operation where a Company neither makes a profit nor a loss.

Break even point in units calculation :

Break even point in units calculation = Fixed Costs for the Period ÷ Contribution per unit

Where, Contribution per unit = Selling Price per Unit less Variable Cost (Manufacturing and Non Manufacturing) per unit

Conclusion :

At Break Even Point level,Total Contribution will equal Total Fixed Cost (thus no profit nor loss)

The only data the question provided is :

Fixec Cost - $305,000