International Foundation Programme in Humanities and Social Sciences IFP3804 MATHEMATICS FOR ECONOMICS 12 MAY 2015 14:30 Duration: 2 hours 30 minutes YOU ARE NOT PERMITTED TO READ THE CONTENTS OF THIS QUESTION PAPER UNTIL INSTRUCTED TO DO SO BY AN INVIGILATOR Answer ALL SIX questions Calculators are permitted in this examination. Please state on your answer book the name and type of machine used. Complete all rough workings in the answer book and cross through any work that is not to be assessed. Possession of unauthorised material at any time when under examination conditions is an assessment offence and can lead to expulsion from QMUL. Check now to ensure you do not have any notes, mobile phones, smartwatches or unauthorised electronic devices on your person. If you do, raise your hand and give them to an invigilator immediately. It is also an offence to have any writing of any kind on your person, including on your body. If you are found to have hidden unauthorised material elsewhere, including toilets and cloakrooms it will be treated as being found in your possession. Unauthorised material found on your mobile phone or other electronic device will be considered the same as being in possession of paper notes. A mobile phone that causes a disruption in the exam is also an assessment offence. EXAM PAPERS MUST NOT BE REMOVED FROM THE EXAM ROOM Examiners: Elmina Homapour Dr Y. G. Makedonis © Queen Mary, University of London, 2015 Page 2 of 4 IFP3804 (2015) Question 1 For a firm with the following total revenue (TR) and total cost (TC) functions: TR(Q) = 150Q – 10Q2 TC(Q) = 2Q3 – 3Q2 + 10Q +49 where Q is the quantity produced (a) Construct a profit function (π) (b) By calculating the vertex of the parabola find: (i) the optimal quantity (Q) to produce (ii) the level of profit (π) obtained (c) Sketch the profit function. Ensure that you identify any points where the curve cuts the axis and label any maximum or minimum points. [20 marks] Question 2 1. A toy maker has a supply equation P = Q2 + 300 and equilibrium observed as Pe = 700, Qe = 20. a. Calculate the producers’ surplus for the toy maker b. Sketch this supply equation, Make sure you label the points at which this equation meets both the x and y axis. Share in the area that represents producer surplus. [20 marks] Question 3 For the economy described below: C = 89 + 0.7Y Consumption Function I = 120 – 100i Investment Function Mt= 0.1Y Transaction-Precautionary Demand for Money Mw = 240 – 250i Speculative Demand for Money MS =275 Money Supply (a) find the level of income Y and the rate of interest i that simultaneously bring equilibrium (b) estimate the level of consumption C, investment I, the speculative demand for money Mw and the transaction-precautionary demand for money Mt [20 marks] IFP3804 (2015) Page 3 of 4 Question 4 For a class of twenty students their scores out of 100 in an in class test for Mathematics were as follows: 55,63,40,80,82,96,21,55,64,69,77,73,90,65,53,55,70,60,74,86 (a) Use the above data to construct a suitable frequency table (b) Represent the data in a suitable graph (c) Calculate the mean and mode test score (d) Calculate the standard deviation for the test score (e) Calculate the Pearson’s first and second coefficients of skewness (f) Using the results from (b) and (d) does the degree of skewness observed in the data suggest that the teacher set a paper that was rather easy for the students? [20 marks] Question 5 The table below shows the number of days, f, in a 40-day period during which X automobile accidents occurred in a city. Fit a Poisson distribution to the data Number of Accidents (x) 0 1 2 3 4 Number of Days (f) 15 10 7 5 3 Total = 40 [10 marks] Turn Over Page 4 of 4 IFP3804 (2015) Question 6 On a final examination in statistics marked out of 100, the mean was 75 and the standard deviation was 10. If the scores were normally distributed, a) determine the proportion of the students who scored at least 63 b) determine the proportion of the students who scored between 58 and 80 [10 marks] End of Paper – An appendix of 1 page follows ______________________________________________________________________________