Aim: Investigate the Determinants of Exam Performance

EC226 Econometrics 1

Assignment 1 2006-7

Aim: Investigate the determinants of exam performance

Introduction

The main objective of this assignment is to investigate how different variables such as age, ability, course and expenditure on alcohol affect an individual's ability to perform in a first year statistics exam. We will examine the effects of such independent variables on the dependent variable qtmark. Achieving this will require the production and analysis of several regressions and the use a variety of statistical tests.

Question 1

Figure 1.1 in the appendix refers to some basic descriptive statistics for the dependent variable qtmark. From the graph it is observed that the bulk of the data lies within marks of 35 to the maximum at 95. The mean mark is 64.65% which is relatively similar to the median at 65. However the difference in these two statistics is likely to have been caused by the anomalous value of 9 at the minimum, which affects the mean but not the median. Importantly the standard deviation of 13.01 is fairly large signifying that the data is widely distributed about the average. The data is skewed negatively to the right.

Figure 1.2 represents a cross-plot between ability and qtmark. The upward sloping scatter graph shows how ability affects an individual's performance in statistics exams. Figure 1.3 is a correlation matrix that shows that there is a mildly positive correlation between the variables of 0.321. Comparing this correlation with that