Problem P 11-20
Highland Automotive wishes to forecast the number of new cars that will be sold next week. The following table summarizes the number of new cars sold during each of the past 12 weeks:
WEEK NUMBER SOLD (a) Provide a forecast by using a 3-week weighted
1 22 moving average technique with weights 5, 3, and
2 26 1 (5 = most recent).
3 23 (b) Forecast sales by using an exponential smooth-
4 27 ing model with a = 0.45.
5 21 (c) Highland would like to forecast sales by using
6 25 linear trend analysis. What is the linear equation
7 28 that best fits the data?
8 26 (d) Which of the methods analyzed here would you use? Explain your answer.
9 29
10 29
11 27
12 31
Problem P 11-28
Consider the patient data for Dr. Schalkoff given in
Problem 11-27.
(a) Draw the relationship between the crime rate and Dr. Schalkoff's patient load. Is a linear model between these two variables reasonable?
(b) Apply linear regression to study the relationship between the crime rate and Dr. Schalkoff's pa- Year Number of Patients Crime Rate
tient load. 1 30 67.3
(c) If the crime rate increases to 140.2 in year 11, 2 27 70.6 how many patients will Dr. Schalkoff treat? 3 34 82.4
(d) If the crime rate drops to 98.6, what is the patient 4 35 84.7 projection?
5 34 90.1
6 49 98
7 54 110.1
8 48 103.8
9 52 112.3
10 55 125.2
Problem P12-24
Blaine Abrams is the owner of a small company that produces electric scissors used to cut fabric. The annual demand is for 75,000 scissors, and Blaine produces the scissors in batches. On average, Blaine can produce 1,000 pairs of scissors per day during the production process. Demand for scissors has been about 250 pairs of scissors per day. The cost to set up the production process is $800, and it costs Blaine $0.90 to carry 1 pair of scissors for one year. How many scissors should Blaine produce in each batch?
Problem P12-26
Chandler Manufacturing has a demand for 1,000 pumps each year. The cost of a pump is $50. It costs Chandler Manufacturing $40 to place an order, and the carrying cost is 25% of the unit cost. If pumps are ordered in quantities of 200, Chandler Manufacturing can get a 3% discount on the cost of the pumps. Should Chandler Manufacturing order 200 pumps at a time and take the 3% discount?