An insight into market share and usage of mobile phones by
students studying BUS1BAN at La Trobe University

Part A:  Sampling

Q1.      What sampling plan did you employ to select your sample of 370 observations? [0.5 mark]

Q2.      Suppose a student opinion survey is to be conducted in order to determine whether breakout rooms should be used during online Zoom classes. Use your own words and describe a possible way to obtain a stratified random sample among all students who are taking BUS1BAN during Semester 2, 2021. [0.5 mark]

Part B: Descriptive Statistics

Q3.      Analysis on phone brand proportion:

1. In the following table, report proportion of the students based on mobile phone brands in your sample. [1 mark]

1. Use an appropriate chart (properly labelled) to display information in Q3-a above, and provide brief interpretation on the chart. [1 mark]

Q4.      Investigating the relationship between mobile phone brands and student gender:

1. Complete the following cross classification table of gender by mobile phone brand. [1.5 marks]

1. Derive a relative frequency cross classification table based on row totals (i.e., gender) using the table in Q4-a above. [1.5 marks]

1. Use an appropriate graph to display the information contained in the cross-classification table of row relative frequencies above. Decide whether there is a relationship between mobile phone brands and the gender. [1 mark]

1. Estimate the 95% confidence interval for the proportion of iPhone (Apple Inc.) users in your sample of 370 students. Briefly interpret your answer. [1.5 marks]

Q5.      Investigating the relationship between earnings and money spent on mobile phone:

1. In the following table, report average monthly earnings and mobile bill of students by gender in your sample. [2 marks]

1. Estimate the 95% confidence interval of the average monthly bill for female students, and interpret your answer. [1.5 marks]
2. Produce a scatter plot (showing trend line, linear equation and R-squared) using Excel, to show the relationship between earnings and money spent on mobile phone for female students. Then interpret the linear equation and R-squared in the scatter plot for female students. [2 marks]

Q6.      Frequency, relative frequency, and cumulative relative frequency

1. Construct a frequency and cumulative relative frequency distribution using the bill data of male students (i.e., complete the table below). [3 marks]

1. Construct a relative frequency histogram and an ogive for the bill data of male students, using the frequency distribution table in Q6-a above. [1 mark]

Part C:  Summary and Discussion

Q7.      Briefly discuss how to determine the relationship between two nominal variables, and how to determine the relationship between two numerical variables. (Note: Use your own words, and talk about the methods in general. No additional calculation is required.) [2 marks]