Business statistics Assignment

ECON 1035 – BUSINESS STATISTICS 1

PROJECT

Due: Week 12: Saturday, 7 October 2017, 7pm (Singapore time)

Instructions:

This is a group assignment with a minimum group size of two and a maximum group size of four. All group members will receive marks according to the percentage of contribution mutually agreed by all group members. All group members must be enrolled in the same lecture class.

The assignment must be provided in the form of a (brief) business report approximately 8-10 pages (including the cover page). The structure of your (brief) business report must include 1] A Title, 2] An Executive Summary, 3] An Introduction, and 4] Conclusions.

You must submit an electronic copy of your assignment in Blackboard. Hard copies will not be accepted. SHOW YOUR WORK for calculation based questions.

This assignment requires the use of Microsoft Excel. If you have Windows, you will also need to use the Data Analysis ToolPak. If you have a Mac with Excel 2011, you will need to use StatPlus:MAC LE.

Group Members

First name	Last name	Student ID	% of contribution

Note: If all contributed equally, please indicate % of contribution for each group member as 100%. Otherwise indicate correct % of contribution made by each group member.

Please indicate your lecturer’s name and lecture time:

Lecturer
Lecture day and time

Problem Description:

A local game retailer has asked us to evaluate global video game sales for the current generation of consoles. We have collected data on 129 video game sales in which globally sold in excess of 1 million units. We have included critic and user score ratings and the type of console.

You will use descriptive statistics, inferential statistics and your knowledge of multiple linear regression to complete this task.

Global Sales (Dependent Variable) and several characteristics (Independent Variables) are given in the Excel file: Assignment data.xlsx. You can find the details of the data in the “Dictionary” tab.

Required:

A. Calculate the descriptive statistics from the data and display in a table. Be sure to comment on the central tendency, variability and shape for Global Sales, Critic Score and User Score. How would you interpret the mean of dummy variables such as Mature or Xone? (1 Mark)

B. Draw a graph that displays the distribution of Global Sales. Be sure to comment on the distribution. Does it appear normally distributed? (1 Mark)

C. Create a box-and-whisker plot for the distribution of User Score and describe the shape. Is there evidence of outliers in the data? (1 Mark)

D. What is the probability that we could randomly select a game where the global sales is greater than 2 million units? What is the likelihood that the sales exceed 2 million units for games that are rated as mature? Is the sales statistically independent of whether they are rated as mature? Use a Contingency Table. (2 Marks)

E. Estimate the 95% confidence interval for the population mean critic score. How does this compare to the 95% confidence interval for the population mean user score? (1 Mark)

F. A fellow student recently stated that any of the major games released, those selling in excess of 5 million units, almost always have a mean user score higher than 60. Test her claim at the 10% level of significance. (1 Mark)

G. Run a multiple linear regression using the data and show the output from Excel. Exclude the dummy variable Xone from the regression results as well as Year. (1/2 Mark). Remember to select the tick-boxes named “Residual plots”, “Line fit plots” and “Normal probability plots”. These graphs will help you to answer Part N below.

H. Is the coefficient estimate for the Critic Score statistically different than zero at the 5% level of significance? Set-up the correct hypothesis test using the results found in the table in Part (G) using both the critical value and p-value approach. Interpret the coefficient estimate of the slope. (2 Marks)

I. Interpret the remaining slope coefficient estimates. Discuss whether the signs are what you are expecting and explain your reasoning. (2 Marks)

J. Interpret the value of the Adjusted R2. Is there a small difference between the R2 and the Adjusted R2? If so, what may explain the reasoning for this? (1/2 Mark)

K. Is the overall model statistically significant at the 5% level of significance? Use the p-value approach. (1/2 Mark)

L. Based on the results of the regressions, what other factors would have influenced global sales? Provide a couple possible examples and indicate their predicted relationship with sales if they were included. (1 Mark)

M. Predict the average sales of a game that is not rated mature with a critic score of 95, a user score of 60 that is released on the WiiU. Discuss if it is appropriate to do prediction under these conditions. Show the predicted regression equation. (1 Mark)

N. Do the results suggest that the data satisfy the assumptions of a linear regression (that is, Linearity, Normality of the Errors, and Homoscedasticity of Errors)? Show using scatter diagrams, residual plots, normal probability plots and/or histograms and Explain. (1 1/2 Marks)

O. Does this data indicate the true population distribution of console sales? Explain and if not, describe a sampling procedure that could lead to more accurate results. (1 Mark)

P. Construct Unweighted Aggregate Sales Indexes for each console using 2013 as a base year. Which console had the strongest growth between 2013 and 2016? (1 Mark)

Allocation of Marks:

Professional Business Report 2 Marks Part A 1 Mark Part B 1 Mark Part C 1 Mark Part D 2 Marks Part E 1 Mark Part F 1 Mark Part G 1/2 Mark Part H 2 Marks Part I 2 Marks Part J 1/2 Mark Part K 1/2 Mark Part L 1 Mark Part M 1 Mark Part N 1 1/2 Marks Part O 1 Mark Part P 1 Mark Total: 20 Marks