1. Smith Travel Research has reported average occupancy and room rates for hotels in the largest U.S. hotel markets. For y = average room rate (dollars) and x = average occupancy rate (percent), fit a second-order polynomial model to the data and determine the percentage of the variation in average room rates that is explained by the model. Given the nature of these variables, comment on causation possibilities that might be present.

   %Occupancy	$Avg Rate
   78.70	80.99
   68.70	82.48
   63.90	76.50
   71.70	101.76
   70.80	100.25
   80.50	169.19
   66.90	78.74
   71.50	86.50
   68.10	76.43
   79.90	118.60
   64.10	70.05
   71.90	91.77
   69.50	99.18
   77.50	111.99
   65.40	72.98
   74.30	116.58
   57.70	64.93
   66.10	70.25
   58.00	74.33
   70.70	90.49
   66.80	73.20
   69.00	76.84
   72.40	89.82
   63.10	68.80
   69.00	104.96
   78.50	74.76

2. Using the data, with y = average dollar sales per call, x1 = years of experience, and x2 = score on the sales aptitude test; fit a second-order model with interaction to the data. Interpret the R² value for the model and indicate whether, at the 0.05 level, the model is significant.

   Avg. $/call	Yrs	Score	Yrs_sq	Score_sq	Yrs*Score
   184.82	1	25.5	1	650.25	25.5
   358.88	4	41.2	16	1697.44	164.8
   468.53	9	65.2	81	4251.04	586.8
   287.02	2	37.0	4	1369.00	74.0
   319.27	3	34.1	9	1162.81	102.3
   593.22	14	87.3	196	7621.29	1222.2
   305.38	2	30.0	4	900.00	60.0
   211.28	1	35.4	1	1253.16	35.4
   515.23	11	82.6	121	6822.76	908.6
   478.21	8	66.6	64	4435.56	532.8
   479.45	11	62.3	121	3881.29	685.3
   522.63	12	90.3	144	8154.09	1083.6
   492.32	10	60.3	100	3636.09	603.0
   460.70	6	67.4	36	4542.76	404.4
   515.48	10	74.9	100	5610.01	749.0
   487.25	12	79.2	144	6272.64	950.4
   491.55	11	85.8	121	7361.64	943.8
   553.66	13	89.5	169	8010.25	1163.5
   395.61	5	47.7	25	2275.29	238.5
   422.78	5	59.7	25	3564.09	298.5

3. Fit the linear trend equation to these data showing the value of shipments of business supplies in billions of dollars. What is the trend estimate for 2010?
   Year: 1994 1995 1996 1997
   Shipments: $258.5 $276.5 $287.10 $302.5
4. The following data shows residential and commercial natural gas consumption (quadrillion Btu) from 1982 through 1997.
   Year Consumption Year Consumption
   1982 25.6 1990 29.4
   1983 25.6 1991 30.1
   1984 26.5 1992 30.0
   1985 26.7 1993 31.1
   1986 26.9 1994 31.4
   1987 27.6 1995 32.3
   1988 28.9 1996 33.7
   1989 29.4 1997 33.7
   For the data above, determine the centered moving average for N = 2; for N = 4.
5. International Dairy Queen, Inc., a firm whose business is highly seasonal, has reported the following quarterly net income figures for 1991 through 1995.

Net Income (Millions)

I II III IV

1991 155 231 270 105

1992 182 255 315 294

1993 160 250 280 297

1994 210 310 365 335

1995 225 325 384 386

1. Construct the four-quarter centered moving average for these data and determine the percentages of the moving average for the quarters.
2. Determine the seasonal indexes for the quarters.
3. Use the seasonal indexes to deseasonalize the original time series.

6. Samples of 12-volt batteries are taken at 30 minute intervals during a production run. Each sample consists of 3 batteries, and a technician records how long each battery will produce 400 amperes during a standard test. Given the data below, construct 3-sigma mean and range control charts and evaluate whether the process is in control.

Minutes, Battery Number

Sample Number 1 2 3

1 13.3 9.4 12.1

2 12.2 13.4 8.5

3 11.2 8.2 9.2

4 7.8 9.7 10.0

5 10.1 11.4 13.8

6 9.9 11.7 8.5

Price: $18.69

Solution: The downloadable solution consists of 11 pages, 769 words and 10 charts.
Deliverable: Word Document