For the data in the Excel file Helpdesk Survey, determine if the mean overall satisfaction ratings differ by the ratings given for response time.
> Use the data in the Excel file MBA Motivation and Salary Expectations to determine how well a linear function models the relationship between pre- and post-MBA salaries. Compare it to a third-order polynomial. Would the polynomial model have a logical ex
> Using the data in the Excel file Kidney, determine the relationship between frailty rates in people with chronic kidney disease and the age of a person by constructing a scatter chart for the data. Find the best-fitting function using the Trendline tool.
> A product manufacturer wishes to determine the relationship between the shelf space of the product and its sales. Past data indicates the following sales and shelf space in its stores: Using these data points, apply simple linear regression and examine t
> For the Excel file Job Satisfaction, develop a regression model for overall satisfaction as a function of years of service and department that has the largest R2. Which department, if any, has the highest impact on satisfaction?
> For the Car Sales data described in Problem 35, develop a regression model for selling price as a function of horsepower and manufacture year, incorporating an interaction term. What would be the predicted price for a car manufactured in either 2002 or
> A leading car manufacturer tracks the data of its used cars for resale. The Excel file Car Sales contains information on the selling price of the car, fuel type (diesel or petrol), horsepower (HP), and manufacture year. a. Develop a multiple linear regre
> A researcher is analyzing the body fat percentage based on the measurements of triceps, thigh, and mid-arm of a person (in inches). The data is recorded in the Excel file Body Fat Percentage. a. Use the Correlation tool to develop the correlation matrix
> The Excel file Women Height Data provides information on women’s height, their mother’s height, their father’s height, amount of protein intake (per day), and the hours of exercise (per day) for a select sample of women. Use the Correlation tool to find
> Each worksheet in the Excel file LineFit Data contains a set of data that describes a functional relationship between the dependent variable y and the independent variable x. Construct a line chart of each data set and use the Trendline tool to determine
> An insurance company is estimating the risk model based on customer age is define as R = aebx where a is a fixed constant and b is a constant that depends on the customer age. They categorize the age into 5 categories as age < 10 with b = 0.05, 10 < age
> The Excel file Credit Approval Decisions provides information on credit history for a sample of banking customers. Use regression analysis to identify the best model for predicting the credit score as a function of the other numerical variables, using bo
> The Excel file Breakfast Foods provides a variety of nutritional information about 67 breakfast food items in supermarkets in different parts of the world. Use regression analysis to find the best model that explains the relationship between calories and
> Use the data in the Excel file Job Satisfaction to find the best multiple regression model to predict the overall satisfaction as a function of the other variables. What managerial implications does your result have?
> Use the data in the Excel file EU Cost of Living Adjustments to find the best multiple regression model to predict the salary as a function of the adjusted cost of living rates. What would the comparable salary be for a country in the European Union with
> Using the data in the Excel file Credit Card Spending, develop a multiple linear regression model for estimating the average credit card expenditure as a function of both the income and family size. Predict the average expense of a family that has two me
> Use the data in the Excel file Neighborhoods to find a multiple regression model to predict the total sales as a function of all the other given variables. State the model and explain R2, Significance F, and p-values.
> Use the data in the Excel file Canned Food to find a multiple regression model to predict the total sales as a function of all the other given variables. State the model and explain R2, Significance F, and p-values.
> Using the data in the Excel file Home Market Value, develop a multiple linear regression model for estimating the market value as a function of both the age and size of the house. State the model and explain R2, Significance F, and p-values.
> The Excel file World Tour Sales provides data on sales (£) and the number of radio, TV, and newspaper ads promoting the world tour for a group of countries. Develop simple linear regression models for predicting sales as a function of the number of each
> A consumer products company has collected some data relating to the advertising costs and sales of one of its products: What type of model would best represent the data? Use the Trendline tool to find the best among the options provided.
> In a toy manufacturing company, the manufacturer needs to pay rent (p) each month and monthly electricity (q). To produce each toy, the company incurs costs for plastic (r) and for cloth (s). The variables p, q, r, and s are positive constants. Given the
> Use the results (Weddings) to analyze the residuals to determine if the assumptions underlying the regression analysis are valid. In addition, use the standard residuals to determine if any possible outliers exist.
> Use the results (Student Grades) to analyze the residuals to determine if the assumptions underlying the regression analysis are valid. In addition, use the standard residuals to determine if any possible outliers exist.
> Use the results (Horsepower versus Gasoline) to analyze the residuals to determine if the assumptions underlying the regression analysis are valid. In addition, use the standard residuals to determine if any possible outliers exist.
> Use the results for Problem 10 (Demographics) to analyze the residuals to determine if the assumptions underlying the regression analysis are valid. In addition, use the standard residuals to determine if any possible outliers exist. Data from Problem 1
> Using the Excel file Weddings, apply the Excel Regression tool using the wedding cost as the dependent variable and the couple’s income as the independent variable, only for those weddings paid for by the bride and groom. Interpret all key regression res
> Using the Excel file Weddings, apply the Regression tool using the wedding cost as the dependent variable and attendance as the independent variable. a. What is the regression model? b. Interpret all key regression results, hypothesis tests, and confiden
> Using the data in the Excel file Student Grades, apply the Excel Regression tool using the midterm grade as the independent variable and the final exam grade as the dependent variable. Interpret all key regression results, hypothesis tests, and confidenc
> The Excel file Horsepower versus Gasoline provides data on the amount of gasoline used per 100 miles by different brands of cars along with their horsepower. a. Construct a scatter diagram for gasoline used per 100 miles and horsepower in the given Excel
> Using the data in the Excel file Kidney, apply the Excel Regression tool using kidney frailty rates and age of a person as the variables. Interpret all key regression results, hypothesis tests, and confidence intervals in the output.
> According to a magazine, people read an average of more than three books in a month. A survey of 20 random individuals found that the mean number of books they read was 2.9 with a standard deviation of 1.23. a. To test the magazine’s claim, what should t
> The yearly government tax revenue (in $ millions) depends on customer income, business profits, and capital gains defined as tax = -2.556 + 3.799 *income + 1.583 * profit + 0.739 * capital. a. Interpret the numbers in this model. b. What is the governmen
> An analyst at a business school in France is assessing students’ performance. Historical records of applicants suggest that the mean score obtained by students attending the school is 350. The business school administration wants to know whether the perf
> A pharmaceutical company in Australia is testing a medical drug that intends to increase heart rate. A sample of 124 tests yielded a mean increase of 1.4 beats per minute, with a population standard deviation known to be 3.6. Since the company wants to a
> Looking at the data and information in the Excel file TV Viewing Survey, state some examples of interesting hypothesis tests by proposing null and alternative hypotheses.
> Conduct a chi-square test to determine if a normal distribution can reasonably model the sum of the midterm and final exam grades in the Excel file Student Grades.
> Conduct a chi-square test to determine if a normal distribution can reasonably model the expense data in the Excel file Travel Expenses.
> Conduct a chi-square test to determine if a normal distribution can reasonably model the data in the Excel file Airport Service Times.
> Four call service representatives were monitored over a period of three months. After each call, every customer was asked whether they were satisfied with the service by answering “Yes” or “No.â
> A manufacturer of automobiles is bringing out a new model. To create its advertising campaign, the manufacturer wants to determine whether the model’s appeal will be dependent on a particular age group. A sample of a customer survey rev
> For the following cross-tabulation data, which represent a count of the type of books that individuals prefer, verify that the assumptions of the chi-square test are not met, and aggregate the data in an appropriate way so that the assumptions are met. T
> Conduct the chi-square test for independence using the aggregated results using a level of significance of 0.05.
> Use the model to predict the total sales for weeks 2 through 16, and compare the results to the observed sales. Does the accuracy of the model seem to be different when coupons are used or not? When advertising is used or not?
> Looking at the data and information in the Excel file Retail Survey, state some examples of interesting hypothesis tests by proposing null and alternative hypotheses.
> The following cross-tabulation shows the number of people who rated a customer service representative as friendly and polite based on whether the representative greeted them first. a. Write the hypotheses for the chi-square test for independence. b. Find
> The cross-tabulation data given below represent the number of passed and failed results of male and female students at a university for the last semester. a. Write the hypotheses for the chi-square test for independence. b. Find the expected frequencies.
> The cross-tabulation data given below represent the number of males and females in a work group who feel overstressed and those who don’t. a. Write the hypotheses for the chi-square test for independence. b. Find the expected frequencie
> For the data in the Excel file Freshman College Data, a. use ANOVA to determine whether significant differences exist in the mean retention rate for the different colleges over the four-year period. b. use ANOVA to determine if significant differences ex
> Using the data in the Excel file Broadband Service Providers, apply ANOVA to determine if the mean response for value for the pound is the same for different types of broadband service providers in the United Kingdom.
> For the Excel file Job Satisfaction, use ANOVA to determine if the mean overall job satisfaction ratings differ by department.
> Looking at the data and information in the Excel file Car Sharing Survey, state some examples of interesting hypothesis tests by proposing null and alternative hypotheses.
> Determine if there is evidence to conclude that rain fall in area A is significantly more than that of area B using the data in the Excel file Rainfall.
> A firm installs 1,500 air conditioners that need to be checked every six months. The firm can hire a team from its logistics department at a fixed cost of €6,000. This team will check each unit for €15.00. The firm can also outsource this at a cost of €1
> For the data in the Excel file Netflix Views Survey, conduct a hypothesis test to determine if married individuals watch less Netflix than single individuals.
> For the data in the Excel file Coffee Shop Preferences, conduct a hypothesis test to determine if price and taste ratings are the same for large/chain stores versus small/independent coffee shops.
> The Excel file Fortune100 Accountants provides the results of a survey of 35 employees in a tax division of a Fortune 100 company. a. Is there sufficient evidence at the 0.01 level of significance that the average number of years of service is the same
> A research group in Sweden estimated that almost 1.5 million people in Sweden have used Netflix from September to December 2018. Formulate an appropriate one-sample test of hypothesis to test this.
> Using the Excel file YouTube Hours, determine if the mean number of hours spent online per week is the same for males as it is for females.
> A two-sample test for means was conducted to determine if the completion time for continuing education programs for nurses differed when costs are paid by employers (Yes) versus when individuals paid out of his or her own funds (No). The following are th
> A two-sample test for means was conducted to test whether the mean number of movies watched each month differed between males and females. The Excel Data Analysis tool results are shown below. a. Explain how to use this information to draw a conclusion i
> The Excel file Room Inspection provides data for 100 room inspections at each of 25 hotels in a major chain. Management would like the proportion of nonconforming rooms to be less than 2%. Formulate a one sample hypothesis test for a proportion and perfo
> Suppose that a previous record of a blood donation campaign conducted in the city of London indicates that the probability of a donor having blood type O is 0.6. Of a sample of 120 donors who have come to donate blood at this year’s blood donation camp,
> A financial advisor believes that the proportion of investors who are risk-averse (that is, try to avoid risk in their investment decisions) is at least 0.6. A survey of 31 investors found that 19 of them were risk averse. Formulate a one-sample hypothes
> For each of the following scenarios, state whether descriptive, predictive, or prescriptive analytics tools would most likely be used. a. An insurance firm wants to analyze fraudulent claims to predict their future losses. b. A store manager has to revie
> Jamie Drout is interested in perceptions of gender stereotypes within beauty product advertising, which includes soap, deodorant, shampoo, conditioner, lotion, perfume, cologne, makeup, chemical hair color, razors, skin care, feminine care, and salon ser
> An industry trade publication stated that the average profit per customer for this industry was greater than $4,500. The Excel file Sales Data provides data on a sample of customers. Using a test of hypothesis, do the data support this claim or not?
> A gym trainer in Cologne, Germany, believes that the average time spent exercising each day by the city is greater than 1.5 hours. Formulate an appropriate one sample test of hypothesis to test this belief.
> A survey on female health stated that the standard body fat percentage of a woman of the average age of 25 years with an average weight of 140 pounds and an average height of 64 inches is 16%. The Excel file Women Body Fat Percentage provides the data fo
> A computer repair firm believes that its average repair time is less than two weeks. Using the data in the Excel file Computer Fix Times, determine if the company can continue to support this claim.
> A diet program claims that the average amount of water that a person on a diet should drink each day to lose weight is 4 liters. A random sample of 13 people enrolled in the diet program found that the average consumption is 3.6 liters of water per day w
> A gum manufacturer claims that on average the flavor of an entire packet of its gum would last for more than 39 minutes. A quality controller selects a random sample of 55 packets of gum. She finds the average time for which the gum flavor lasts is 40 mi
> Using the data in the Excel file Consumer Transportation Survey, test the following null hypotheses: a. Individuals spend at least eight hours per week in their vehicles. b. Individuals drive an average of 600 miles per week. c. The average age of SUV dr
> A pharmacist believes that in manufacturing a pill or tablet medicine, the need for an active ingredient in each pill is less than 14 milligrams. She selects a random sample of 15 pills and determines that each pill has an average of 10.5 milligrams of t
> A marine biologist wants to use a parrotfish for research purposes as she believes that the variability of weights among parrotfish is small. From a random sample of 50 parrotfish, she found that their mean weight is 6.3 pounds with a standard deviation
> When President Donald Trump took office, he believed that the reason he did not win the popular vote was because 3 to 5 million people voted illegally. Explain how hypothesis testing might be used in a similar fashion as the legal analogy example.
> An important part of planning manufacturing capacity is having a good forecast of sales. Elizabeth Burke is interested in forecasting sales of mowers and tractors in each marketing region as well as industry sales to assess future changes in market share
> Suppose that the mean score for the mathematics test cited in Problem 7 is 607. What is the probability that a random sample of 324 students will have a mean score of more than 619? Less than 588?
> In one region in your country, suppose that the standard deviation of monthly expenditure of the residents is about $7,000. In a random sample of 380 residents, what is the standard error of the mean monthly expenditure?
> Based on extensive data from a national high school educational testing program, the standard deviation of national test scores for mathematics was found to be 118 points. If a sample of 324 students are given the test, what would be the standard error o
> Using the Excel file Diabetes Check, draw five random samples by repeating the sampling experiment for sample sizes 10, 15, and 20. For each sample sizes, find the stabilized glucose point estimates for the mean and standard deviation. Estimate the sampl
> After launching a new range of health drinks, a local fitness company conducted a survey to understand how the products were being received. From a random sample of 500 customers, who were asked to participate in the survey, 230 had bought the new produc
> A gym instructor records the weights of a random sample of 31 male high school students. The mean weight was found to be 140 pounds and the standard deviation of this population is 20 pounds. How large a sample should be selected to estimate that the mea
> If a manufacturer conducted a survey among randomly selected target market households and wanted to be 99% confident that the difference between the sample estimate and the actual market share for its new product was no more than 6%, what sample size wou
> Trade associations, such as the United Dairy Industry Association, frequently conduct surveys to identify characteristics of their membership. If this organization conducted a survey to estimate the annual per capita consumption of milk and wanted to be
> The Excel file High Blood Pressure records the results of 30 individuals who were tested for hypertension. Use the Excel Sampling tool to obtain a random sample of 5 individuals and compute point estimates for the mean and standard deviation for the syst
> A survey of 23 patients at a hospital found 95% confidence intervals for the following: Construct a stock chart-based visualization of these confidence intervals. What conclusions can you draw from the chart?
> In reviewing the data in the Performance Lawn Equipment Database, Elizabeth Burke noticed that defects received from suppliers have decreased (worksheet Defects After Delivery). Upon investigation, she learned that in 2014, PLE experienced some quality p
> For the data in the Excel file Debt and Retirement Savings, find 95% confidence intervals for the mean income, long-term debt, and retirement savings for individuals who are single and individuals who are married. What conclusions can you reach by compar
> For the data in the Excel file Education and Income, find 95% confidence intervals for the mean annual income of males and the mean annual income of females. Can you conclude that the mean income of one group is larger than the other?
> Due to rapid developments in technology, the number of laptops per household has also increased. A study was conducted for two housing areas to determine the average number and proportion of laptops per household in both areas. The data recorded by the s
> The Excel file Professionality shows select lecturers at a university and their related information such as gender, status of current position, number of years in current position, highest degree, number of years of working since obtaining the degree, an
> A survey of 270 individuals found that one-sixth of them use their cell phones primarily for email. Can you conclude statistically that the population proportion who use cell phones primarily for email is less than 0.20?
> A survey of 50 young professionals found that they spent an average of $20.21 when dining out, with a standard deviation of $13.88. Can you conclude statistically that the population mean is greater than $23?
> According to Moovit Insights website, the average amount of time people in Singapore spend commuting to and from work, on a weekday, using public transport is 84 minutes. Recent studies have shown that 90% of people in Singapore took public transports to
> Using the data in the Excel file Accountants, find and interpret 90% confidence intervals for the following: a. mean years of service b. proportion of employees who have a graduate degree Use the appropriate formulas and Excel functions.
> A study was conducted to examine the time spent on studying by students at a university and whether they pass or fail a course. It found that to pass or fail a course the standard deviation were 5 hours and 7 hours, respectively. The study also found tha
> For the data in the Excel file Debt and Retirement Savings, find 95% confidence intervals for the mean income, long-term debt, and retirement savings. Use the appropriate formulas and Excel functions.
> Elizabeth Burke has identified some additional questions she would like you to answer using the Performance Lawn Equipment Database. 1. Are there significant differences in ratings of specific product/service attributes in the Customer Survey worksheet?
> The Excel file Diabetes Check contains the records of patients with diabetes who have received treatment at a local hospital. Number each row in the dataset and help the hospital to select a simple random sample of 20 unique results by using the Excel Sa
> For the data in the Excel file Grade Point Averages, find 90%, 95%, and 99% confidence intervals for the mean GPA. Compute the confidence intervals using the appropriate formulas and verify your results using the Excel Confidence Intervals template.
