Betty Yeager has been operating a dental practice for the past five years. As part of her practice, she provides a dental hygiene service. She has found that her costs for this service increase with patient load. Costs for this service over the past eight months are as follows:

Month	Patients Served	Total Cost
May	320	$2,000
June	480	$2,500
July	600	$3,000
August	200	$1,900
September	720	$4,500
October	560	$2,900
November	630	$3,400
December	300	$2,200

Required:

1. Determine the cost estimation model using the high-low method.

2. Estimate the cost of dental hygiene services for January for 450 patients using the cost estimation model from (1).

3. Determine the cost estimation model using the method of least squares/regression analysis.

4. Estimate the cost of dental hygiene services for January for 450 patients using the cost estimation model/regression analysis from (3).

5. Determine the coefficient of determination/R2. What does this measure tell you about the cost estimation model from (3)?