**Please show me how to do the excel spread sheet. step by step**

Cairns believes that the overhead is affected by total monthly direct-labor hours. Cairns decided to perform a least-squares regression of Overhead on total direct labor hours.

1. Develop cost formula for overhead cost using least square regression method by constructing excel spreafsheet.

2. The overhead rate developed from the least-squares regression is different from Cairns' preliminary estimate of $18 per direct labor hour. Explain the difference in the two overhead rates

Outside Environment, Inc. provides commercial landscaping services in San Diego. Sasha Cairns, the firm's owner, wants to develop cost estimates that she can use to prepare bids on jobs. After analyzing the firm's costs, Cairns has developed the following preliminary cost estimates for each 1,000 square feet of landscaping Direct material $390 Direct labor (5 direct-labor hours at $11 per hour) 55 Overhead (at $18 per direct-labor hour) 90 Total cost per 1,000 square feet $535 Cairns is quite certain about the estimates for direct material and direct labor. However, she is not as comfortable with the overhead estimate. The estimate for overhead is based on the overhead costs that were incurred during the past 12 months as presented in the following schedule. The estimate of $18 per direct-labor hour was determined by dividing the total overhead costs for the 12-month period ($1,296,000) by the total direct-labor hours (72,000). Regular Direct Overtime Direct Total Direct Total Overhead Labor Hours Labor Hours Labor Hours January $ 108,000 5820 380 6,200 February 94,000 4,760 40 4800 March 36,000 4420 B0 4,500 April 112,000 5,180 420 5,600 May 114,000 6,060 940 7,000 June 130,000 6,480 1,520 8,000 July 128,000 6,760 1,240 8,000 August 112,000 6,100 700 6,800 September 106,000 5,520 BO 5600 October 94,000 5,540 80 5,600 November 84.000 4240 B0 4,300 December 108,000 5,120 480 5,600 $1,226,000 66,000 6,000 72.000 "The overtime premium 50 percent of the area-labor wage rates, Total