Instructions: Please answer the questions in the prescribed format. Marks and feedback comments are expected to be posted on LEO by Sep, 10, 2018, 9 am. Question 1 (14 marks) Do you think daily temperatures have an impact on coffee consumption? A café manager noted the number of coffee sold in a random sample of 50 days, which had very different daily temperatures, over a year. Required a) Compute the following descriptive statistics with the data provided: (4 marks) i) Mean:_______________________ ii) Median:______________________ iii) Standard Deviation:_____________ iv) Coefficient of Variation:_________ Note: Please include the workings as part of your answer. b) Draw a boxplot of the data. (2 marks) c) If you were the café manager, would you form an opinion that daily temperatures have an impact on the variation of coffee consumption (high, medium or low), based on your answers in a) and b)? Please explain. (3 marks) i) High, medium or low:__________________________ ii) Justification:________________________ d) Please suggest 2 plausible factors other than daily temperatures that you consider would have an impact on coffee consumption. Could you explain the impact of each of these two factors on coffee consumption with the same data provided? Please explain. (5 marks) i) Factor 1:_____________________ ii) Factor 2:_____________________ iii) Yes or no:____________________ iv) Explanation:__________________ Question 2 (12 marks) a) The following is a line chart of crimes over a period of 21 years in Country ABC. Required (4 marks) i) What is your opinion on the trend of violent crimes? ii) Please suggest a factor (other than the factors in b) and c)) and explain how the factor would have an impact on the trend. i) Opinion on trend:_________________ ii) Factor:_____________________________________ Explanation on impact:_________________________ b) The following is a scatter plot of the same violent crimes data versus a demographical variable: size of population. Required (4 marks) i) What is your opinion on the trend of violent crimes against the size of the population? ii) Please suggest a plausible explanation on how the size of population would have an impact on the frequency of violent crimes as depicted by the data. i) Opinion on trend:_____________________________________ ii) Plausible explanation on impact:_________________________ c) There is a belief that a large proportion of the violent crimes are committed by people age 15 to 24. The following is a scatter plot of the same violent crimes data versus a second demographical variable: population aged between 15 and 24. Required (4 marks) i) What is your opinion on the trend of violent crimes against the population aged between 15-24? ii) Please suggest a plausible explanation on how the size of population aged between 15-24 would have an impact on the frequency of violent crimes as depicted by the data. i) Opinion on trend:_____________________________________ ii) Plausible explanation on impact:_________________________ Question 3 (4 marks) What is the most important lesson you have learnt in presentation and interpretation of statistical data from undertaking the assignment? Please explain. i) Lesson: ___________________________________________ ii) Explanation: ____________________________________________

## Suppose that 0 was inside of the 95% confidence interval.

Suppose that 0 was inside of the 95% confidence interval.From that measure,could you conclude that the water became cleaner? Why or why not? Suppose that 0 was outside the 95% confidence interval.From that measure,could you conclude that the water became cleaner? Why or why not?Suppose that 0 was inside of the 95% confidence interval.From that measure,could you conclude that the water became cleaner? Why or why not? Suppose that 0 was outside the 95% confidence interval.From that measure,could you conclude that the water became cleaner? Why or why not?

## A bank employs two appraisers.

Question:1. A bank employs two appraisers. When approving borrowers for mortgages, it is imperative that the appraisers value the same types of properties consistently. To make sure that this is the case, the bank evaluates six properties that the appraisers had valued recently. (15 points)Property123456Apraiser 1235,000195,000264,000315,000435,000515,000Apraiser 2239,000190,000271,000310,000437,000525,000a. Enter the data into Minitab. Using the 5% level of significance determine whether there is a significant difference between the average values estimated by appraiser 1 and appraiser 2. Show and follow the 7 steps of hypothesis testing. . (8 points)b. Construct a 95% confidence interval to estimate the average difference between appraisers. make asentence or two using your result. (4 points)c. What assumption is required for this test? Use an appropriate graph or other method to determine if the assumption is met. Discuss your findings. (3 points)Property123456Apraiser 1235,000195,000264,000315,000435,000515,000Apraiser 2239,000190,000271,000310,000437,000525,000a. Enter the data into Minitab. Using the 5% level of significance determine whether there is a significant difference between the average values estimated by appraiser 1 and appraiser 2. Show and follow the 7 steps of hypothesis testing. . (8 points)b. Construct a 95% confidence interval to estimate the average difference between appraisers. make asentence or two using your result. (4 points)c. What assumption is required for this test? Use an appropriate graph or other method to determine if the assumption is met. Discuss your findings. (3 points)

## Employers explores current work- force analytics and planning practices, investments, and future plans. U.S.

Question 1, Page 37, 2.7Visier’s 2014 Survey of Employers explores current work- force analytics and planning practices, investments, and future plans. U.S.-based employers were asked what they see as the most common technical barrier to workforce analytics. The responses, stored in barriers , were as follows:Barriers FrequencyData must be integrated from multiple sources 68Lack of automation/repeatable process 51Metrics need to be identified or defined 45Production is cumbersome 42Data quality is not reliable 36Sharing findings is challenging 21Analytic tools are too complex 17Ensuring security and integrity of workforce data 17 Other 3Source: Data extracted from The State of Workforce Analytics and Planning, 2014 Survey Report, available at bit.ly/1zuM99Z.a. Compute the percentage of values for each response need. b. What conclusions can you reach concerning technical barriers to workforce analytics?Question 2, Page 37, 2.9A study of selected Kickstarter projects showed that overall a majority were successful, achieving their goal and raising, at a minimum, the targeted amounts. In an effort to identify project types that influence success, selected projects were subdivided into project categories (Film & Video, Games, Music, and Tech- nology). The results are as follows:OutcomeCATEGORYSuccessfulNo SuccessfulTotalFilm & Video17,02426,85743,881Games 5,10510,07515,180Music19,27517,05036,325Technology2,5568,77011,326Total43,96062,752106,702Source: Kickstarter.com, kickstarter.com/help/stats.a. Construct contingency tables based on total percentages, row percentages, and column percentages.b. Which type of percentagerow, column, or totaldo you think is most informative for these data? Explain.c. What conclusions concerning the pattern of successful Kick-starter projects can you reach?Question 3,Construct a stem-and-leaf display, given the following data from a sample of mid-term exam scores in finance:445988834364Question 4,The following is a set of data from a sample of n= 11 items:X:869471351069Y:265109173865Construct a scatter plot. Show your workIs there a relationship between X and Y? ExplainQuestion 5,The following data is about the cost of electricity (in $) during July 2012 for a random sample of 50 0ne-bedroom apartments in a large city.96171202178147102153197127821571859011617211114821313016514114920617512312814416810916795163150154130143187166139149108119183151114135191137129158Construct a frequency distribution and a percentage distribution that have class intervals with the upper class boundaries $99, $119, and so onConstruct a cumulative percentage distributionAround what amount does the monthly electricity cost seem to be concentratedQuestion 1, Page 37, 2.7Visier’s 2014 Survey of Employers explores current work- force analytics and planning practices, investments, and future plans. U.S.-based employers were asked what they see as the most common technical barrier to workforce analytics. The responses, stored in barriers , were as follows:Barriers FrequencyData must be integrated from multiple sources 68Lack of automation/repeatable process 51Metrics need to be identified or defined 45Production is cumbersome 42Data quality is not reliable 36Sharing findings is challenging 21Analytic tools are too complex 17Ensuring security and integrity of workforce data 17 Other 3Source: Data extracted from The State of Workforce Analytics and Planning, 2014 Survey Report, available at bit.ly/1zuM99Z.a. Compute the percentage of values for each response need. b. What conclusions can you reach concerning technical barriers to workforce analytics?Question 2, Page 37, 2.9A study of selected Kickstarter projects showed that overall a majority were successful, achieving their goal and raising, at a minimum, the targeted amounts. In an effort to identify project types that influence success, selected projects were subdivided into project categories (Film & Video, Games, Music, and Tech- nology). The results are as follows:OutcomeCATEGORYSuccessfulNo SuccessfulTotalFilm & Video17,02426,85743,881Games 5,10510,07515,180Music19,27517,05036,325Technology2,5568,77011,326Total43,96062,752106,702Source: Kickstarter.com, kickstarter.com/help/stats.a. Construct contingency tables based on total percentages, row percentages, and column percentages.b. Which type of percentagerow, column, or totaldo you think is most informative for these data? Explain.c. What conclusions concerning the pattern of successful Kick-starter projects can you reach?Question 3,Construct a stem-and-leaf display, given the following data from a sample of mid-term exam scores in finance:445988834364Question 4,The following is a set of data from a sample of n= 11 items:X:869471351069Y:265109173865Question 5,The following data is about the cost of electricity (in $) during July 2012 for a random sample of 50 0ne-bedroom apartments in a large city.96171202178147102153197127821571859011617211114821313016514114920617512312814416810916795163150154130143187166139149108119183151114135191137129158Around what amount does the monthly electricity cost seem to be concentrated

## define, compare, and contrastsimple linear regression andmultiple regression.

define, compare, and contrastsimple linear regression andmultiple regression.explainlinear correlation andscatterplots.explain and define thepredictor variable orexplanatory variable. Please explain and define theresponse variable.Which of the variables just above aredependent? Which areindependent?Suppose you are given data from a survey showing the IQ of each person interviewed and the IQ of his or her mother. That is all the information that you have. Your boss has asked you to put together a report showing the relationship between these two variables. What could you present and why?define, compare, and contrastsimple linear regression andmultiple regression.explainlinear correlation andscatterplots.explain and define thepredictor variable orexplanatory variable. Please explain and define theresponse variable.Which of the variables just above aredependent? Which areindependent?Suppose you are given data from a survey showing the IQ of each person interviewed and the IQ of his or her mother. That is all the information that you have. Your boss has asked you to put together a report showing the relationship between these two variables. What could you present and why?

## By using a computer algorithm, an investigator can assign members of twin pairs

By using a computer algorithm, an investigator can assign members of twin pairs at random to an intervention condition in a clinical trial. Assume that each twin pair consists of dizygotic twins (one male and one female). The probability of assigning one member of the pair to the intervention condition is 50%. Among the first four pairs, what is the probability of assigning to the intervention condition: 1) zero females, 2) one female, 3) two females, 4) three females, 4) four females?

## he article “Why We Fall for This” (AARP Magazine, May/June 2011) described a stu

he article “Why We Fall for This” (AARP Magazine, May/June 2011) described a study in which a business professor divided his class into two groups. He showed students a mug and then asked students in one of the groups how much they would pay for the mug. Students in the other group were asked how much they would sell the mug for if it belonged to them. Surprisingly, the average value assigned to the mug was quite different for the two groups! Indicate whether the study is an observational study or an experiment. Give a brief explanation for your choice.

## Table 4.16 shows results of an eight-center clinical trial to compare a drug to

Table 4.16 shows results of an eight-center clinical trial to compare a drug to placebo for curing an infection. At each center, subjects were randomly assigned to groups. a. Analyze these data, describing and making inference about the group effect, using logistic regression.

## FROM: Chapter on Statistical Inference Concerning Two Populations (Data set and

FROM: Chapter on Statistical Inference Concerning Two Populations (Data set and excel formula workbook for problem attached)The Speedo LZR Racer Suit is a high-end body-length swimsuit that was launched in February 2008. Wehn 17 world records fell at the December 2008 Short Course Championships in Croatia, many believed a modification in the rules surrounding swimsuits was necessary. The FINA Congress, the international governing board for swimming, banned the LZR Racer and all other body-length swimsuits from competition effective Jan 2010. In a statement to the public, FINA defended its position with the following statement: “FINA wishes to recall the main and core principle that swimming is a sport essentially based on the physical performance of the athlete”.Luke Johnson, a freelance journalist, wonders if the decision made by FIJNAhas statistical backing. He conducts an experiment with the local university’s Division I swim team. He times 10 of the swimmers swimming the 50 Meter breaststroke in his bathing suit and then retests them while wearing the LZR Racer. A portion of the results are shown int he accompanying table (see attached excel for dataset).1.) In a report (using the attached excel formulas) determine whether the LZR Racer significantly improves swimmers times at the 5% significance level. Assume that the time difference is normally distributed.2.) Comment on whether the data appear to support FINAs decision.

## The accompanying table shows annual return data from 2001-2009 for Vanguard’s Ba

The accompanying table shows annual return data from 2001-2009 for Vanguard’s Balanced Index and European Stock Index mutual funds.(excel attached) A. )Set up the hypotheses to test whether the mean returns of the two funds differ. (Hint: This is a matched -pairs comparison) B.)At the 5% level of significance, determine if the mean weight gain of women due to pregnancy is more than 35 pounds.