Question 1: Consider the following information.
2000 2003
Item Price Quantity Price Quantity
A $ .25 210 $ .37 210
B .87 2 1.15 2
C 10.00 4 15.00 4
D .35 35 .60 35
a. Compute the Laspeyres index.
b. Compute the Paasche index.
c. Comment on your answers for Parts c and d.
Question 2: The following time series shows the sales of a clothing store over a 10-week period.
Week Sales ($1,000s)
1 15
2 16
3 19
4 18
5 19
6 20
7 19
8 22
9 15
10 21
a. Compute a 4-week moving average for the above time series.
b. Compute the mean square error (MSE) for the 4-week moving average forecast.
c. Use 0.3 to compute the exponential smoothing values for the time series.
d. Forecast sales for week 11.
Question 3: Fifteen people were asked to indicate their preference for domestic versus imported cars. The following data showed their preferences.
Individual Domestic vs. Imported
1 +
2 +
3 -
4 +
5 +
6 +
7 -
8 +
9 +
10 +
11 +
12 +
13 +
14 +
15 -
With = 0.05, test for a significant difference in the preferences for cars. A "+" indicates a preference for imported cars
Question 4: Two faculty members ranked 12 candidates for scholarships. Calculate the Spearman rank-correlation coefficient and test it for significance. Use a .02 level of significance.
Rank by Rank by
Candidate Professor A Professor B
1 6 5
2 10 11
3 2 6
4 1 3
5 5 4
6 11 12
7 4 2
8 3 1
9 7 7
10 12 10
11 9 8
12 8 9
Question 5: Independent random samples of ten day students and ten evening students at a university showed the following age distributions.
Day Evening
26 32
18 24
25 23
27 30
19 40
30 41
34 42
21 39
33 45
31 35
Use 0.05 and test for any significant differences in the age distribution of the two populations. Use Wilcoxon Signed-Rank Test.
Question 6 : A production process that is in control has a mean () of 80 and a standard deviation () of 10.
a. Determine the upper and the lower control limits for sample sizes of 25.
b. Five samples had means of 81, 84, 75, 83, and 79. Construct an X bar chart and explain whether or not the process is in control.