Please help me identify the correct answers and the reason as to why, for the question below, so I can better understand the material.

The Surgical Care Unit of Silver Care Health Group uses the high-low method to predict its total surgical unit supplies costs. It appears that nursing hours worked is a good predictor of surgical unit supplies costs in the unit. The supervisor for the unit has gone through the records for the past year and has found that June had the fewest nursing hours worked at 950 hours, while September had the most nursing hours worked at 1,480 hours. In June, total surgical unit supplies cost $31,000 and in September, total surgical unit supplies cost $41,600. If plans for the Surgical Care Unit call for 975 nursing hours to be worked next month, what is the expected surgical unit supplies cost for the month? Use the high-low method to determine the variable and fixed costs components of the Surgical Care Unit of Silver Care Health Group's operating cost equation. First identify the formula and calculate the variable cost component (slope). Change in costs Change in volume Variable cost per unit