Cost Behavior Analysis; Correlation Analysis; Standard Error of the Estimate. The following data have been collected by the controller of Lynpax Corporation over the past 12 months:

Maintenance Machine Month Cost Hours January. $ 2,200 2,500 February. 2,130 2,350 March. 2,000 2,000 April. 2,170 2,400 May. 2,050 2,100 June. 2,220 2,600 July. 2,150 2,450 August. 2,250 2,550 September. 2,290 2,700 October. 2,150 2,450 November. 2,210 2,400 December. 2,100 2,300 Total. $25,920 28,800 Required:

(1) Using the high and low points method, determine the average amount of fixed maintenance cost per month and the variable maintenance rate per machine hour.

(2) Determine the fixed cost and the variable cost rate, using the method of least squares.

(3) Compute the coefficient of correlation, r, and the coefficient of determination, r2, between the machine hours and the maintenance cost.

(4) Compute the standard error of the estimate.

(5) Determine the 95% confidence interval for maintenance cost at the 2,500-machine-hour level of activity.