MOCK EXAM ANSWERS Qs1 & 2

4BDIN001w Exam Questions for Mock session in week 12 workshop

The exam in January will take 1 hour 30 minutes.  Calculators (not phones) will be allowed.  The following questions give examples of the type of question.  Students should aim to be able to answer all questions in the mock set out below within the 1 hour 30 minutes allowed for the actual exam.  Long essay type answers are not expected. 

Questions such and 3, 6, 7 and 8 may be answered with bullet points or lists.  The key is to support these with relevant examples, etc to demonstrate understanding.  The marks for Q3 for example would awarded on the basis of 1 per type, 1 per example and 1 per means of addressing the problem.  So a student providing 5 relevant types, 5 relevant examples and 5 means of addressing these issues could expect to gain the whole 15 marks.

Q1                                                                                                                               10 Marks

	Year 1	Year 2	Year 3	Year 4	Year 5
Oil	18.00	21.00	22.00	20.00	19.00
Water	5.00	6.00	8.00	9.00	11.00
Treating Year 1 as your base year calculate the % change over 5 years
If you rebase to year three what is the % change over the last 3 years
If you rebase to year  four what is the % change over the last 2 years
What comments can you make about the cost of oil by comparison to the cost of water?

Oil over 5 years:  (19 X 100)/18 = 105.5556 therefore 5.5% change

Oil over 3 years:  (19 X 100)/22 =  86.36 therefore -13.36% change

Oil over 2 years:  (19 X 100)/20 = 95 therefore -5% change

Water over 5 years:  (11 X 100)/5 = 220 therefore 120% change

Water over 3 years:  (11 X 100)/8 = 137.5 therefore 37.5% change

Water over 2 years:  (11 X 100)/9 = 122.22 therefore 22.2% change

Over the five year period both the price of oil and water has increased, (oil by 5.5% and water by 120%).   If you look at oil over a two or three year period it goes down by 5% and 13.4% whereas water rises year on year.

Please refer to week 4 lecture and week 9 seminar materials

Q2                                                                                                                               15 Marks

A) Plot the following onto two scatter graphs, one for each data set:

Store 1	Monday	Tuesday	Wednesday	Thursday	Friday	Saturday
Number of Thefts	6	2	3	5	8	4
Security Staff	2	4	4	3	2	3

Store 2	Monday	Tuesday	Wednesday	Thursday	Friday	Saturday
Number of Telephone calls	46	67	73	36	51	58
Security Staff	3	5	6	2	4	4

B) Having plotted both sets of data please comment on any correlation in either set of data

C) From looking at your scatter plots what might the expected impact of having 4 Security staff in Store 1 on Friday be? 

D) Explain how you can draw this conclusion

E) If you had 6 security staff in Store 1 on any given day what impact would you anticipate this having on thefts

F) If you reduced the number of security staff to 1 on any given day in store 2 what impact might you expect this to have on the number of Telephone calls?

A)

Line of best fit included - top marks

Correctly plotted good marks

B) Negative correlation for thefts, positive correlation for telephone calls

C) That thefts would drop to 2 or 3

D) You can draw this conclusion from looking at the graph showing the negative correlation between theft and staff numbers.  Where staff numbers are 4 thefts have been 2 and 3.

E) Based on the line of best fit you could anticipate that there would be no thefts.

F) Dropping the number of staff to 1 could be expected to see a reduction in the number of calls to between 25 and 30/ below 30.