Assignment 1

Using the data files provided and your data analysis skills gained in Modules 4-8, answer all the Questions to provide advice to help with the decision making on the issues described in the case studies below.

QUESTION 1 [15 marks = 0.5+1.5+3+1+0.5+5+3.5 marks]

Preamble

Tupps Motors, which was established in the year 2000, sells 5 brands of new passenger vehicles Holden, Toyota, Ford, and Mitsubishi and Nissan which were the market leaders in 2000. As years passed the General Manager of Tupps Motors, Brian Tupps, noticed that brands such as Holden, Ford, and Nissan are not selling as much as they used to. In 2018, Brian Tupps discusses his observation with his recent Business graduate son, Ben Tupps, and they both decided to collect Australia-wide sales data of the top 10 brands of passenger vehicles in 2018 to see how the market share of the different brands has changed. In 2020, the pandemic struck, and business was not in good shape, but Brian managed to keep the business and his employees functioning with pandemic subsidies provided by the Federal government. With the closure of the production of Holden in Australia in 2021, Brian wanted Ben to analyze the Australia-wide post-pandemic sales data for 2022 and provide him with advice on the market share of the 10 brands of passenger vehicles.

Data

Data on the number of passenger vehicle sales for the top 10 brands of passenger vehicles in 2018, 2020, and 2022 are provided in the file Sales-1.xlsx. [Note that to make comparisons easier Ben collected data for the same top 10 brands of passenger vehicles. As Holden sales ceased in 2021, Ben has excluded Holden from the Top 10 passenger vehicles for this analysis.]

Analysis

• Identify the type of data that Ben has collected for the various brands of passenger
• Comment on the movement in the TOTAL sales of the top 10 passenger vehicles in 2018,2020 and
• Use an appropriate chart to display the market share of the top 10 brands of passenger vehicles in Comment on the market leaders.
• In 2018, considering the market shares displayed in the chart in part (c), what would be Ben’s advice to Brian about the top 5 brands of passenger vehicles based on the 2018 market
• Would it be appropriate to make decisions based on the 2020 sales
• Use an appropriate chart to display the market share of the top 10 brands of passenger vehicles in 2022. Has the market share of the brands changed between 2018 and 2022? Comment on the top 5 brands that Ben should Brian to consider for his Would the advice be different between the two years and why? (Max 150 words)
• Using an appropriate chart, present the sales of the top 10 passenger vehicles sales in Australia in 2018 From what you observe from the chart, present a comparison of changes in sales by brand between 2018 and 2022 (Max 100 words)

Preamble

In the last part of the 20th century, scientists developed the theory that the planet was warming and that the primary cause was the increasing amounts of atmospheric carbon dioxide (CO2), which are the product of burning oil, natural gas, and coal (fossil fuels). Although many climatologists believe in the so-called greenhouse effect, many others do not subscribe to this theory. Further, Earth’s temperature has increased and decreased many times in its long history. We have had higher temperatures and we have had lower temperatures, including various ice ages. In fact, a period called the ‘little ice age’ ended around the middle to the end of the nineteenth century. Then the temperature rose until about 1940, at which point it decreased until 1975. In fact, a Newsweek article published 28 April 1975, discussed the possibility of global cooling, which seemed to be the consensus among scientists at the time. There are two critical questions that need to be answered in order to resolve the issue.

1. Is Earth actually warming?
2. If the planet is warming, is CO2 the cause?

In terms of data, the generally accepted procedure is to record monthly temperature anomalies. To do so, we calculate the average for each month over many years. We then calculate any deviations between the latest month’s temperature reading and its average. A positive anomaly would represent a month’s temperature that is above the average. A negative anomaly indicates a month where the temperature is less than the average.

Data & Analysis

PART 2A [11 Marks = 3 + 8 marks] Is Earth actually warming?

File GLOBALA.xlsx contains the monthly temperature anomalies (°C) from March 1958 to May 2016. Using the data answer the following:

• Considering the monthly temperature anomalies data over the data period 1958-2016, use a graphical technique to display the Discuss the trend in data. (Max 25 words)
• We conclude that there is global warming if the average temperature anomalies over a period is Considering the average of the temperature anomalies (m), perform a hypothesis test to show that there is global warming using a 5 percent level of significance. [Hint: Calculate the sample mean and sample standard deviation of the monthly temperature anomalies for the sample period 1958-2016 and test the hypothesis that the population mean temperature anomaly (m) is positive (m > 0?). You are required to follow the 6-step procedure of hypothesis testing].

PART 2B [4 Marks] If the planet is warming, is CO2 the cause?

Data for CO2 levels (ppm) in the atmosphere together with the temperature anomalies for March 1958 to May 2016 are stored in file GLOBALB.xlsx.

• Use a graphical technique to determine whether there is a linear relationship between temperature anomalies and CO2 On the plot, insert the trend line and the coefficient of determination R². Considering the slope, can we conclude that CO2 is the cause of global warming? Comment on the fitness of the fitted trend line and the validity of your decision.