The marketing department of a large organisation is analysing the monthly sales results for two subsidiaries, A and B, over the past 60 months. The monthly sales figures (£000) were as follows:
Monthly Sales (£000) Subsidiary A Subsidiary B
Under 20 13 8
20-30 12 6
30-40 12 9
40-50 9 10
50-60 5 12
Over 60 9 15
a. For each subsidiary, construct an OGIVE and use it to estimate the median and inter-quartile range for the monthly sales figures. (plots: 3; estimates: 2)
b. Comment on any differences between the two subsidiaries.
c. A manager wishes to know what proportion of months in the last 5 years each subsidiary had a sales figure under £30,000, between £30,000 and £50,000, and over £50,000. Using the most appropriate format and clear titles and labels, create a graphical representation of the required information.
d. What is the probability that, in any given month, both subsidiary A and subsidiary B would have sales over £40,000? Show your calculations.
e. What is the probability that, in any given month, Subsidiary B would have sales in either the under £40,000 or the over £60,000 range? Show your calculations
