Worksheet

Activity 1.

The volume of sales by month in a department store for the year 20X4 were as follows:

£

670,000

680,000

685,000

683,000

690,000

710,000

712,000

710,000

690,000

680,000

685,000

660,000

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

(a) Plot these sales on a graph.

(b) Isolate the trend by using a scattergraph

Activity 2

The following time series shows a set of sales figures for eight quarters, which are clearly

increasing.

Year

20X4

20X5

Quarter Sales

£000

1

3

2

5

3

5

4

5

1

7

2

9

3

9

4

9

Identify the trend using a 4 quarter moving average.

1

Activity 3

The following data represents the sales for TS limited for the eight quarters shown:

Year 1

Year 2

Q1

74

84

Q2

100

106

Q3

94

120

Q4

127

141

(a) Plot the above data.

(b) Calculate the trend using moving averages.

(c) Plot the trend.

Activity 4

X Ltd is forecasting its sales for the four quarters of 20XS. It has carried out a linear

regression exercise on its past sales data and established the following:

a=20

b=0.7

The equation of the regression line is therefore:

y = 20 + 0.7x

When x is number of the quarter and y is the sales value in £000s.

Calculate the sales for each of the quarters in 20X5.

Activity 5

A regression line has been calculated as y = 192 + 2.40x, where

x is the output and

y is the total cost.

You are required to:

(a) Explain this formula.

(b) Use it to predict the total cost for (i) 500 units and (ij) 1,500 units.

Activity 6

Given below are the estimated trend figures for a company's sales for the next four quarters:

20X3

£

Quarter 1

560,000

Quarter 2

580,000

Quarter 3

605,000

Quarter 4

632,000

The seasonal variations using the multiplicative model have been calculated as:

Quarter 1 + 15%

Quarter 2 + 10%

Quarter 3 -5%

Quarter 4 -20%

Calculate the forecast sales figures for each of the next four quarters....