ETF2121/ETF5912 Data Analysis in Business Assignment 2 Submission guidelines: • The assignment must be submitted through Moodle using the link Assignment 2 Online Submission. No email submission is accepted. • The assignment must be submitted before May 14th (Friday), 11:30pm (Australian Eastern Standard Time). Please take into account possible internet disruptions and leave ample time to upload your document. You can submit your assignment early if you wish. • You are allowed to upload one document with maximum size 100MB. You can either type down your answers in one Word document, or take photos of handwritten answers then convert them to one PDF document. Your work must be clear and legible. If it cannot be read, or read only with difficulty, your assignment will be returned to you unmarked and you will receive a zero mark for this assignment. • I recommend using apps such as Camscanner (available on both iPhones and Android smart phones) to converts photos of your handwritten answer into the PDF document. This app lets you take a photo then crop and stretch the page so it is aligned and easy to read. The app will also combine multiple pages into one PDF document. Assignment guidelines: • This assignment covers topics from lecture 5 to 8 and tutorials 5 to 8. • This is an individual assignment. • Answer the questions directly. Do not undertake inappropriate tests or discuss irrelevant matters. • This assignment is worth 15 marks. 1 Question A (4 marks) A real estate agent claims that a house’s appraisal value is higher than its selling price on average in a Melbourne suburb. She collected the selling price and the appraisal value for 25 recently sold houses in this suburb. The mean and standard deviation of the selling price, the appraisal value, and the differences between the two (Differences = Selling−Appraisal) are presented in Table 1. Table 1: House price (in thousands) Selling Appraisal Difference Mean 861 875 −14 Standard Deviation 104 78 23 1. Identify the sampling design used to obtain the data in Table 1. 2. The standard deviation of the differences (between selling price and appraisal value) is much smaller than the standard deviation of selling price or appraisal value. Briefly explain why. 3. Assume the differences are normally distributed. Use the p-value approach in hypothesis testing to evaluate the real estate agent’s claim at the 5% significance level. Write down the five steps of hypothesis testing (use appropriate Excel functions to conduct you analysis but do not copy/paste a screenshot of your Excel output). Present your test statistic and p-value rounded to three decimal places. Question B (3 marks) Suppose a golf association wants to compare the mean distances associated with four brands of golf balls when struck by a driver. Ten balls of each brand are used in the experiment. The experiment randomly selects 10 golfers; each golfer hit four balls, one from each brand, in a random sequence. The distances are recorded in A2_golfball.xlsx. 1. Identify the sampling design used by the golf association. 2. From this data, is any difference between the mean distances associated with the four brands of golf balls when struck by a driver? Use a 10% significance level for the test. Write down the five steps of hypothesis testing (use appropriate Excel functions to conduct you analysis but do not copy/paste a screenshot of your Excel output). Present your test statistic and p-value rounded to two decimal places. 2 Question C (4 marks) A gym consultant hypothesis that single people go to gym more often than married people. He surveyed 6 single people and 7 married people using the following questionnaire, where a score for each answer are given alongside the answer. • How often do you go to gym? Less than once a week 1 once a week 2 2~3 times a week 3 4~6 times a week 4 More than 6 times a week 5 The answers from the 13 people are recorded in Excel file A2_gym.xlsx. Use the data to answer the following questions. 1. Discuss the sampling design used by the consultant. 2. Do the data support the consultant’s hypothesis that single people go to gym more often than married people at the 5% level? Write down the five steps of hypothesis testing (use appropri- ate Excel functions to conduct you analysis but do not copy/paste a screenshot of your Excel output). Question D (4 marks) Marketers are interested in how social media (e.g. Facebook and twitter) activity are related to the box office revenues of movies. Researchers collected the opening weekend box office revenue (in millions of dollars) for a sample of 23 recent movies. In addition, researchers obtained the tweet rate of each movie (average number of tweets referring to the movie per hour) in the week prior to the movie’s release. The data are recorded in Excel file A2_boxoffice.xlsx. Use EViews to answer the following questions. 1. Present a scatterplot of the data with the fitted line. 2. Write down a population linear regression model. 3. Use EViews to estimate the coefficients and write down the point estimate of the intercept and the slope coefficient (do not copy/paste EViews output). 3 4. Write down the sampling distribution of the slope coefficient using the relevant statistics from EViews output. What assumptions are needed to obtain this sampling distribution? 5. From the OLS estimates, how would the revenue change (on average) if the tweet rate increases by 50? 4























































































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