Question: Compute the daily change of the closing

> 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.

> A survey of 23 individuals found that they spent an average of $39.48 on headphones to use for exercising. The margin of error for a 95% confidence interval was found to be 21.2. a. What are the lower and upper limits of the confidence interval? b. What

> A sample of 40 individuals at a shopping mall found that the mean number of visits to a restaurant per week was 2.88 with a standard deviation of 1.59. Find a 99% confidence interval for the mean number of restaurant visits. Use the appropriate formula a

> A survey of 34 freshmen found that they get an average of 6.26 hours of sleep each night. A 90% confidence interval had a margin of error of 0.509. a. What are the lower and upper limits of the confidence interval? b. What was the standard deviation, ass

> A random sample of 100 teenagers was surveyed, and the mean number of songs that they had downloaded from the iTunes store in the past month was 9.4 with the results considered accurate being within 1.4 (18 times out of 20). a. What percent of confidence

> Each can of a certain brand of sweet corn contains an average of 375 corn kernels with a standard deviation of 8 in each can. Yesterday, Winnie went to a local store and purchased four cans of corn. a. Find the probability that the average number of corn

> In determining automobile mileage ratings, it was found that the mpg in the city for a certain model is normally distributed, with a mean of 41 mpg and a standard deviation of 1.8 mpg. Suppose that the car manufacturer samples five cars from its assembly

> Suppose that the mean monthly expenditure of the region identified in Problem 8 is $15,500. What is the probability that the random sample of 380 residents will have a mean monthly expenditure of more than $15,000? Less than $14,500?

> Your college or university wishes to obtain reliable information about student perceptions of administrative communication. Describe how to design a sampling plan for this situation based on your knowledge of the structure and organization of your colleg

> The background for this case was introduced in Chapter 2. This is a continuation of the case in Chapter 6. For this part of the case, propose and test some meaningful hypotheses that will help Ms. Drout understand and explain the results. Include two-sam

> Students in the new MBA class at a state university have the following specialization profile: Finance—83 Marketing—36 Operations and Supply Chain Management—72 Information Systems—59 Find the probability that a student is either a finance or a marketin

> Answer the following by referring to the scenario described in Problem 4. a. Let A be the event “without blue marble.” Find P(A). b. Let B be the event “first marble selected is green.” Find P(B). c. Let C be the event “last marble selected is red.” Find

> Refer to the ball scenario described in Problem 3. a. Let A be the event with the sum of the selected two balls is an odd number. Find P(A) and P(Ac). b. What is the probability that the sum of the two balls will not be more than 5? c. What is the probab

> The latest nationwide political poll in a particular country indicates that the probability for the candidate to be a republican is 0.55, a communist is 0.30, and a supporter of the patriots of that country is 0.15. Assuming that these probabilities are

> Apply the chi-square goodness of fit test to the data in the Airport Service Times Excel file to determine if an exponential distribution models the data. Use bins of width 100. Note that for an exponential distribution, the number of degrees of freedom

> Apply the chi-square goodness of fit test to the data in the Airport Service Times Excel file to determine if a normal distribution models the data. Use bins of width 100. Note that for a normal distribution, the number of degrees of freedom for the CHIS

> The actual delivery time from a pizza delivery company is exponentially distributed with a mean of 28 minutes. a. What is the probability that the delivery time will exceed 31 minutes? b. What proportion of deliveries will be completed within 25 minutes?

> According to WHO, around 1.35 million people die each year due to road accidents. Suppose that on a specific highway, an average of four accidents occur within every hour. Find the probability that the duration between accidents is less than or equal to

> According to historical data, a European musician finds that customers who download music from a popular Web service spend approximately €24 per month, with a standard deviation of €4. Find the probability that a customer will spend at least €22 per mont

> In reviewing your previous reports, several questions came to Elizabeth Burke’s mind. Use point and interval estimates to help answer these questions. 1. What proportion of customers rate the company with “top box” survey responses (which is defined as s

> A fisherman found that the average length of cherry hybrid salmon is about 20 inches with a standard deviation of 2 inches. By assuming the cherry salmon’s length is normally distributed, find the probability that its length is a. more than 25 inches. b

> A box contains marbles of four different colors: red, green, blue, and yellow. Three marbles are randomly chosen from the box. a. List all possible outcomes in the sample space. b. What is the probability of each outcome?

> A popular soft drink is sold in 2-liter (2,000-milliliter) bottles. Because of variation in the filling process, bottles have a mean of 2,000 milliliters and a standard deviation of 18, normally distributed. a. If the process fills the bottle by more tha

> The distribution of SAT scores in math for an incoming class of business students has a mean of 610 and standard deviation of 20. Assume that the scores are normally distributed. a. Find the probability that an individual’s SAT score is less than 600. b.

> In determining bike mileage ratings, it was found that the mpg (X) for a certain model is normally distributed, with a mean of 34 mpg and a standard deviation of 1.9 mpg. Find the following: a. P(X < 33) b. P(31 < X < 38) c. P(X > 36) d. P(X > 33) e. The

> A student is drawing a rectangle, which has a perimeter of 20 cm. He wants the length, x cm, of one side of this rectangle to be uniformly distributed between 1 cm and 7 cm. Find the probability that the length of the longer side of the rectangle is more

> The time required to play a game of Battleship™ is uniformly distributed between 20 and 60 minutes. a. Find the expected value and variance of the time to complete the game. b. What is the probability of finishing within 30 minutes? c. What is the probab

> The number and frequency of hurricanes over a certain ocean, annually from 1945 through 2020, is shown here. For instance, this means that no hurricanes occurred during 6 of these years, only one hurricane occurred in 16 of these years, and so on. a. Fin

> A life insurance consultant sells three life insurance policies on an average per week for which she receives a fee. Use Poisson’s distribution to calculate the probability that in a given week she will sell a. some policies. b. two or more policies but

> A transport company is inspecting 80 trucks it owns. The inspection determines that the probability of trucks failing the inspection is 0.25. Find the probability that not more than 10 trucks failed the inspection. What is the probability that 75 or more

> The background for this case was introduced in Chapter 2. This is a continuation of the case in Chapter 4. For this part of the case, compute confidence intervals for means and proportions and analyze the sampling errors, possibly suggesting larger sampl

> A popular resort hotel has 300 rooms and is usually fully booked. About 7% of the time a reservation is canceled before the 6:00 p.m. deadline with no penalty. What is the probability that at least 285 rooms will be occupied? Use the binomial distributio

> A glass jar contains 10 balls with labels of numbers 1 to 10. Two balls are randomly selected from the glass jar without replacement. a. Determine the number of combinations possible in the sample space. List all possible elements of the sample space. b.

> During one 12-week period, a particular mutual fund outperformed the S&P 500 index 37 out of 60 days. Find the probability that it would perform as well or better again.

> A major application of analytics in marketing is determining customer retention. Suppose that the probability of a long-distance carrier’s customer leaving for another carrier from one month to the next is 0.16. What distribution models the retention of

> From a bag full of colored balls (red, blue, green, and orange), a few are picked out and replaced. This is done 1,000 times and the number of times each colored ball is picked out is, blue balls = 300, red balls =200, green balls = 450, and orange balls

> Padini Concept, a local retail store in Malaysia, recorded the number of shoes purchased by customers (1 pairs, 2 pairs and 3 pairs) based on the number of clothes purchased (1, 2, and 3) for a random sample of 250 customers. The following data was recor

> The number of children per family was determined and summarized in the following table. Find the expected number, variance, and standard deviation of the number of children per family.

> A consumer products company found that 44% of successful products also received favorable results from test market research, whereas 11% had unfavorable results but nevertheless were successful. That is, P(successful product and favorable test market) =

> The students at Sk&Atilde;&para;vde University, Sweden, have elected five candidates to represent them on the college management council. The committee summarized the age and gender of the members as follows: This group of student representatives decide

> Based on the scenario in Problem 3, what is the probability of first selecting ball 1 and then selecting ball 3? Will it be different if the first ball is replaced in the glass jar? Explain the difference between these two scenarios. Data from Problem 3

> PLE has developed a prototype for a new snow blower for the consumer market. This can exploit the company’s expertise in small-gasoline-engine technology and also balance seasonal demand cycles in the North American and European markets to provide additi

> A survey of shopping habits found the percentage of respondents that use technology for shopping as shown in Figure 5.30. For example, 17.39% only use online coupons; 21.74% use online coupons and check prices online before shopping, and so on. a. What i

> A grocery shop is taking stock of its inventory. The shopkeeper found that out of 120 tins with damaged labels, there are 50 tins of beans, 20 tins of sardines, 35 tins of processed meat, and the rest are tins of soup. a. Find the probability that the ti

> Sue and Dave always spend their evenings together, either cycling or playing computer games. On an evening with good weather, the probability that Sue prefers cycling is 0.7 and for Dave it is 0.4. Find the probability that on a particular fine evening,

> In the past week, an ice-cream kiosk sold 15 cups of chocolate flavor, 22 cups of vanilla, and 13 cups of strawberry. a. Estimate the probability of sale of each flavor for the following week. b. Define the definition of probability used to determine the

> Use the Histogram tool to construct frequency distributions and histograms for weekly usage and waiting time in the Excel file Car Sharing Report. Do not group the data into bins.

> A community health status survey obtained the following demographic information from the respondents: Compute the relative frequencies and cumulative relative frequencies of the age groups.

> Airbnb is an online marketplace for arranging or offering lodging, primarily homestays, or tourism experiences. Airbnb provides a platform for hosts to accommodate guests with short term lodging and tourism-related activities. Guests can search for lodgi

> Use the Manufacturing Measurements Data Excel file to compute sample means, assuming that each row in the data file represents a sample from the manufacturing process. Plot the sample means on a line chart, compute the standard deviation of the sample me

> The Excel file Employee Selection contains role of employees in an organization, along with other specifics—gender, salary, years of education, date of birth, and whether they are citizens of the country. Analyze the data using all the tools that have be

> The Excel file Auto Survey contains a sample of data about vehicles owned, whether they were purchased new or used, and other types of data. Use the appropriate statistical tools to analyze these data. Summarize the observations that you can make from th

> One of PLE&acirc;&#128;&#153;s manufacturing facilities produces metal engine housings from sheet metal for both mowers and tractors. Production of each product consists of five steps: stamping, drilling, assembly, painting, and packaging to ship to its

> Use the COUNTIF function to construct frequency distributions for gender, preferred genre, and influence, develop column charts to express the results visually, and compute the relative frequencies based on the data in the Excel file Video Streaming Serv

> Use the following approaches to analyze the survey data in the Excel file Insurance Survey. ■ Frequency distributions and histograms for the ratio variables (age, years employed, and satisfaction) ■ Descriptive statistical measures for the ratio variable

> Suppose that the average height of all professional basketball players is 6 feet with standard deviation of 5 feet. A player of interest to you is 5.5 feet. Would you consider this player as the outlier? Why

> For the Excel file TV Viewing Survey, is there a significant correlation between (1) the number of TVs in a home and the hours of viewing per week, and (2) age and hours of viewing per week?

> The Excel file House Sales lists a sample of the area (in sq. ft) and prices (in dollars) of various houses. Compute the covariance and correlation between the area and prices.

> Use the Excel file Test Scores and Sales, developed by nine salespersons during the past year, to find the coefficient of correlation between the test scores and sales.

> Find the correlation between weekly food expenditure and monthly household income in the Excel file Food Expenditure.

> For the Peoples Choice Bank database, use PivotTables to find the average transaction amount for each account and branch.

> Use the Excel file Graduation Employment to analyze the average salary and the average percentage of failure rate in interviews among the graduates from the different colleges. What conclusions do you reach?

> Using PivotTables, find the mean and standard deviation of sales by region in the Sales Transactions database.

> The CFO at Performance Lawn Equipment, Brian Ferguson, wishes to design a minimum variance portfolio of index funds to invest some of the firm&acirc;&#128;&#153;s cash reserves. The funds selected for consideration and their variance covariance matrix an

> In the Excel file Debt and Retirement Savings, use a PivotTable to find the mean and standard deviation of income, long-term debt, and retirement savings for both single and married individuals.