Question 1:
The table below gives two samples selected from 10 supermarkets of the weekly sales of a popular soft drink. The first sample gives the details for a normal shelf display of the product, while the second sample gives the details for an end-aisle shelf display. Assuming equal variances, establish, at the 5% level of significance, whether there is a statistically significant difference in the mean weekly sales for the two display locations.
|
Normal display
|
End-Aisle Display
|
|
22
|
52
|
|
34
|
71
|
|
52
|
76
|
|
62
|
54
|
|
30
|
67
|
|
40
|
83
|
|
64
|
66
|
|
84
|
90
|
|
56
|
77
|
|
59
|
84
|
Question 2
The table below gives the quarterly enrollment in a major American business college for the period 2007-2010.
|
Year
|
Winter
|
Spring
|
Summer
|
Autumn
|
|
2007
|
2033
|
1871
|
714
|
2318
|
|
2008
|
2174
|
2069
|
840
|
2413
|
|
2009
|
2370
|
2254
|
927
|
2704
|
|
2010
|
2625
|
2478
|
1136
|
30
|
1 Draw to scale a time series graph representing the above data.
2 Using the ratio-to-moving-average method, determine the quarterly seasonal indices.
3 Interpret the quarterly pattern of enrolment.
4 Compute the trend equation. (6) 4.5 Forecast the 2011 enrolment by quarter.