Abdulrahman Company is developing a cost function for its total costs using the high-low method. The following data have been collected for the past year:

Number of

units produced

Quarter Total Costs

1 5,000 SAR 850

2 6,500 925

3 7,000 950

4 8,000 1,000

Calculate the following amounts:

a. The variable cost per unit

b. The fixed cost

c. The estimated total cost for 9,000 units