STT100: Business Statistics- Research Report Assignment

Internal Code: MAS6777

Research Report Assignment:

Task: Introduction Imagine you have just been hired as a part of the graduate recruitment program at Acme Accounting Services Pty Ltd. Once you pass a six-month probation period, the firm will sponsor you to complete your Chartered Professional Accounting (CPA). The firm offers accounting and analytical services to other businesses. You’ve been given a client account to help with Polytechnic Plumbing Services, who provide emergency and regular plumbing services to consumers and small businesses. Your manager is preparing an annual review for Polytechnic Plumbing and has asked you to look into a series of specific questions asked by the business. Questions: Message received From: Adam Abacus Subject: Fwd: Polytechnic Plumbing Review questions Received: 4 th December 17:00 Attachments: See Excel file download in MyPIA Hi, Congratulations on receiving a graduate position here at Acme Accounting! I’m glad to have you on board. Here’s your first assignment… Please see the below email (and attachment) from a client, Polytechnic Plumbing. I’m preparing an annual review for them and need to address their specific questions. Can you please look into the questions and get back to me with answers that I can copy and paste into the review? (This means you’ll need to restate each question in your own words and answer it one to three full sentences). Also, please keep your calculations in the Excel file and send it back with your written answers. It’s important to always know how we worked out what advice to give clients, in case there are later issues. I need these back by close of business (5pm) on Friday the 9 th of February 2018. If you have any problems before then, please contact me in advance so we can sort them out. Thank you. Adam Forwarded message From: Walter Waterson Subject: Polytechnic Plumbing Review questions Received: 4 th December 13:00 Hi Adam, I know my annual review is due mid-February and I have some specific questions I want addressed. I’ve also attached an Excel file with some data. I refer to the sheet names in italics. Please see below. Incoming call numbers 1. We recently implemented a new phone system that captures data on all incoming calls. The only automated report it produces looks like the image below. Can you tell me what each of the numbers mean? 2. I searched Google to try and understand the above plot and it looked like it was left-skewed. Am I correct? What does this actually mean? 3. From searching Google about the above plot, it also looks like we only got two calls one day, but the quietest day I can remember in the last few months was around 35 calls. What could have happened here to get that number? 4. The system produces day-to- day totals, which are in the CallNumbers sheet, which was used to generate the above box-plot. Is this “2” an “outlier”? Are any others? Can you give statistical evidence that it’s an outlier? If so, I can use these to raise an issue with the phone system provider… Call Survey 5. My reception team has been following up every job we do. They have collected data on customer satisfaction for customers who are willing to participate in a short survey. The data are in the CallSurvey sheet. Can you please tell me the mean and standard deviation customer satisfaction rating (1-5)? 6. Can I please see a chart that compares the average satisfaction rating for each job type? 7. I’m interested in how many survey responses we got for each job type. Can you give me the AVERAGE TYPE of call? [Note from Adam: The average type of call is not possible. Please explain to Walter why we can’t do this and provide some numbers to answer his real question.] Call durations 8. I want to know if our call durations have improved over the last few years. Our previous accounting firm generated the following chart in 2015 for our Annual General Meeting, but we don’t have the raw data anymore. Can you please approximate the mean and standard deviation for the call times from the chart? 9. We just started capturing call-duration data in the last few days. This is in the CallLog sheet. Can you please also calculate the mean and standard deviation for this sample of recent calls in the CallLog sheet? 10. Can you please let me know how these differ from the 2015 call durations and what might have changed in the business to cause the difference? Customer Ratings on Facebook 11. We’re considering allowing customers to rate our service on our Facebook page. Based on the data from the CallSurvey sheet, can you tell me the probability of receiving a five-star rating? [Note from Adam: I’ve put together a contingency table and pasted it below to help you with this.] 12. I really need our Facebook ratings to be either 4 or 5 stars. Can you tell me the probability that jobs classified as “Improvements” will be rated LESS than 4 stars? 13. I want to include an average of Facebook ratings in our advertising. I’m thinking of only inviting customers to rate us on Facebook the job was an emergency or maintenance so the “Improvements” customers don’t bring down average our rating score. What do you think? Confidence in Satisfaction Scores 14. I am aware that the customer ratings collected in the CallSurvey sheet are just for a sample of three typical days and so the actual customer satisfaction could be slightly different if we had a bigger sample. How can I know this data in CallSurvey is reliable? Can you provide some information to give me 95% confidence in the overall satisfaction score? 15. I also want to know how reliable the differences are in satisfaction scores between job type. Can you provide some information to give me 95% confidence in the satisfaction score for each job type? 16. Based on the last question, is the satisfaction score between each job type really that different? How do you know? Changing Business Mix 17. The “Improvements” jobs have always been difficult. Customers usually get several quotes and we must be very competitive on price. It often ends up costing us more than we expected. I’m wondering if we should stop trying to offer home improvement plumbing work and just focus on growing the “emergencies” side of the business. I’ve calculated the basic return on investment (ROI) for each of the jobs in the CallLog sheet. Based on that data, can you tell me if the ROI for the “Emergencies” job type is really lower than the ROI of the “Improvements” job type? [Note from Adam: This is an important business decision, so you need to conduct an appropriate statistical test with alpha of 95% and formally report the relevant statistics.] 18. I tried to work out the above question on my own. After some web searches, I got very confused. Can you give me a very brief explanation of what the null hypothesis is and whether it was accepted in the above answer? 19. If this sample data shows a difference in ROI between the “Emergencies” and “Improvements” job types, what is the probability of your statistical test being incorrect? What type of error is this called? 20. What are your thoughts on changing the business mix to do more “Emergencies” jobs and fewer “Improvements” jobs? [Note from Adam: Assume Walter can increase the “Emergencies” side of the business. Comment on the overall satisfaction data and the comparison of ROI between the two job types. Be factual, avoid personal opinion, and conclude with a recommendation]. Thanks for looking into all these questions, Adam. Let’s have lunch soon. Kind regards, Walter Compose a reply to Adam below To: Adam Abacus Subject: Re: Fwd: Polytechnic Plumbing Review questions