MCD2080: Business Statistics代写
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MCD2080: Business Statistics代写
MCD2080: Business Statistics
Assignment 2: Linear Regression
Status Individual
Hurdle Not applicable
Weighting 5
%
Word limit None
This assignment is marked out of 40 and is worth 5% of the assessment in this unit.
Data Output
You must use Excel to generate the relevant output. The file
MCD2080_A2_T316.xlsx
· contains the assignment data in the worksheet labelled
Data; and
· has appropriatelylabelled locations for graphs, comments and tables in the
Results worksheet.Include your name and student ID in cells B1:B2.
We recommend that you
· create your graphs and tables in the
Data worksheet.
(You
must work in this way on some computers, e.g. network computers, because Excel’s
Data Analysis Toolsmay work only on the worksheet where the data resides.)
· then copy your graphs and tables and paste them to the appropriate locations in the
Results worksheet.
Submission
· Include your name and student ID in cells B1:B2 of the
Results worksheet.
· Your assignment submission is
a printout of your completed
Results worksheet.
The
Results worksheet has been set up to make printing easy, but it is your responsibility to ensure that all required information
is printed on the pages that you hand in.
·
Do not print out the data in the
Data worksheet.
· The presentation of the assignment is important, and some marks are allocated for this. Your work must be easy to read. However, elaborate features are not required.
· For questions involving written comments, the size of the textboxes on the
Results worksheet are an indication (based on 11point font) of the length of comments required. You may adjust the size and shape of the textboxes, especially when this is necessary to arrange the worksheet for printing.
Keep OnTrucking Co.(
KOTC) wants to predict the yearly maintenance expense for a truck from the distance driven during the year. Last year’s data arein the
Data worksheet of
MCD2080_A2_T316.xlsx. The variables are:
§
Truck the truck’s ID.
§
Distance driven last year’s distance travelled in thousands of kilometres (,000km).
§
Maintenance expense last year’s maintenance cost ($).
For this question, place all tables, graphs and comments in the designated spaces in the
Results worksheet of
MCD2080_A2_T316.xlsx.
(a) In
Textbox (a),

discuss the relationship that you expect to findbetween Maintenance Expense and Distance driven.

statethe dependent variable.Briefly explain your choice.
[2 marks]
(b) In
Graph (b), produce a scatterplot of
Maintenance Expensevs
Distance driven, with
Maintenance Expense on the vertical axis.This scatterplot must have appropriate axes labels and an appropriate title.
[2marks]

In Textbox (c),

from what you observe in the scatterplot, describe the relationship between the variables. Interpret this relationship in context of the question.

compare the relationship with your expectations in part (a)(i).

explain whether the relationship between these variables is probabilistic or deterministic.
[3.5 marks]
(d) Use the
Regression function in Excel’s
Data Analysis Tools to generate regression output for the data and place it in
Regression output (d) in the
Results worksheet. In order to check whether you have conducted the regression correctly, make sure that the Standard Error value (fourth number from the top of the output) is equal to 274.9828.
[2 marks]

In Textbox (e),

state,to 3 decimal places, the value of the correlation coefficient.

interpret this value.
[2 marks]
(f) In
Textbox (f),
i. test whether the data provide statistical evidence of a linear relationship between
Maintenance Expense and
Distance driven. Use the pvalue method and a 5% significance level. Show your working.
ii. interpret the conclusion of your test in context of the question.
[6 marks]

In Textbox (g),
i. write down the estimated regression equation of the line of best fit for the data. Define any
variables that you use. Show the coefficients in the equation to 3 decimal places.
ii. state the value of the slope of the equation and interpret its value in the context of the
question.
iii. state the value of the intercept of the equation and interpret its value in the context of the
question.Discuss whether it is valid in this case.
[8 marks]

In Textbox (h),

state the value of the coefficient of determination,giving the value to 4 decimal places.

interpret this value.

comment on the goodness of fit of the equation.

suggest one other factor (apart from Distance Driven) that may influence Maintenance
Expense.
[3.5 marks]
(i) In
Textbox (i),
i. obtain a 95% confidence interval for the slope coefficient,giving your answer to 2 decimal places.
ii. interpret this confidence interval.
[4 marks]
(j) In
Textbox (j), predict the maintenance expense when the distance driven is
i. 12,000km. Comment on the likely validity of this prediction. Show your working.
ii. 40,000km. Comment on the likely validity of this prediction. Show your working.
[5 marks]
Presentation
Your presentation should be easy to read. Ease of reading is assisted by appropriate font size, borders, colour choice and labelling in graphs, as well as care in spelling, grammar and punctuation. Marks may be deducted for poor presentation.
[2 marks]
MCD2080: Business Statistics代写