Nike, Inc. provides the following data for its production costs over six months:

Month	Units Produced	Total Costs
Jan	5,000	$50,000
Feb	7,000	$65,000
Mar	6,000	$55,000
Apr	8,000	$70,000
May	9,000	$80,000
Jun	10,000	$90,000

Required:

1. Use the high-low method to estimate the fixed and variable costs.
2. Determine the cost function.
3. Discuss the limitations of the high-low method in cost estimation.