# Stats 50 multipe choice questions set 2015

You must use data provided on various worksheets of the file embedded below to answerseveral questions on this exam. Worksheet names correspond to question numbers.Use the following table for Questions 1-4.The table below shows data for 10 pet owners who visited EmergiCare Vet Clinic.

1) The experience rating is most likely collected through:A. Focus GroupB. SurveyC. Direct ObservationD. Experiment

2) How many variables are quantitative?A. 1B. 2C. 3D. 43) Experience Rating is a(n)___________variable.A. IntervalB. OrdinalC. RatioD. Nominal4) “Breed” is measured as a(n)________variable.A. Ordinal, since some breeds are better than othersB. Ratio, since there is no inherent zeroC. Interval, since there is inherent zeroD. Nominal, since breeds are a categoryIn the Excel file embedded on page 2, use the Worksheet Q5-8 to answer Questions 5-8.5) Using the 2k > n rule, how many classes would be needed for a frequency distribution ofvisual weld defects?A. 4B. 5C. 6D. 76) The independent variable isA. Time, it is not affected by changes in the other variableB. Not time, but a specific type of scatter plot in which the data points in the scatter plot areconnected with a lineC. Visual weld defects shown as a variable in the scatter plot that is influenced by changes inthe other variableD. A visual picture of the relationship between two data points that are paired together on agraph with a horizontal and vertical axis7) Which Stem and Leaf plot depicts the visual weld defects?

2

3

8) Which Scatter plot depicts the visual welding defects?

4

9) Given Pareto chart directly below, on which two errors should management focus theirefforts?

A.B.C.D.

Long delays directly lead to delivery errorsDelivery errors and long delaysEmployee input errors and shipping delay errorsPareto chart gives no insight

10) The Pareto chart above is aA. a bar chart that groups several values side by side within the same category in a horizontaldirectionB. a bar chart that shows in a decreasing order the frequency of the categories that causequality control problemsC. a variable in the scatter plot that is influenced by changes in the other variableD. none of the aboveIn the Excel file embedded on page 2, use the Worksheet Q11-14 for Questions 11-14.The worksheet shows sales data from a local cell phone store detailing the number of cell phonessold for the month of September. This data is a sample of their overall sales.11) What is the mean number of cell phones sold during the month?A. 37.41B. 35.50C. 36.17D. 36.0012) Use the method shown in our book to compute and report the median number of sales duringthe month of September?A. 35.0B. 35.5C. 36.0D. 36.513) Use the book’s method to report the number of sales corresponding to the 45th percentile?5

A.B.C.D.

32.033.034.035.0

14) What is the variance of sales?A. 14.02B. 196.48C. 212.72D. 203.25In the Excel file embedded on page 2, use the Worksheet Q15 for Question 15.The data is from a small store that recently began offering a new and one-of-a-kind product. Thenumbers relate to the first 15 days of sales, and include all sales data to date for this item.15) What is the standard deviation of the sales of this new item?A. 3.97B. 12.81C. 3.58D. 4.6216) Product A has sold a mean of 27 items each day with a standard deviation of 5.4. Product Bhas sold a mean of 35 items with a standard deviation of 6.5. Which product has been moreconsistent in sales?A. Sales of Product A has been more consistentB. Sales of Product B has been more consistentC. Sales of both products are equally consistentD. Cannot be determined17) A data set of unknown distribution has a mean of 60 and a standard deviation of 7. At leasthow much of the data lies between 46 and 74?A. 95%B. 99.7%C. 68%D. 75%Use the following table for Questions 18 and 19. It is a sample of radar-indicated speed ofautomobiles on a particular section of a highway.Speed45-4950-5455-5960-6465-6970-74

Frequency25711155

18) What is the mean speed of the automobiles?6

A.B.C.D.

63.659.562.265.0

19) What is the standard deviation of the speed of these automobiles?A. 6.66B. 44.40C. 6.22D. 6.74For Questions 20 – 26, use the following information. Use 4 decimals in your calculations.As part of an IT survey, both staff and managers were asked to indicate what business andtechnical skills are critical to their jobs. In total, 12 skills were included in the survey. One of the12 skills was “Analyzing Data”. The following table reports findings about that skill:Professional PositionAnalyzing DataStaffManagementTotalCritical4,3743,6338,007Not critical3,4362,6316,067Total7,8106,26414,07420) What is the probability that a person selected at random is a manager?A. 0.4451B. 0.2581C. 0.6329D. 0.554921) What is the probability that a randomly selected person says Analyzing Data is critical skill?A. 0.6221B. 0.2441C. 0.4451D. 0.568922) What is the probability a randomly selected person is a manager and believes Analyzing Datais a critical skill?A. 0.4537B. 0.2581C. 0.5800D. 0.445123) What is the probability that a randomly selected person is a manager or believes AnalyzingData is a critical skill?A. 0.4451B. 0.2581C. 0.7559D. 0.244124) Given that a person is a manager, what is the probability that he/she believes Analyzing Datais a critical skill?7

A.B.C.D.

0.25810.45370.58000.7263

25) The respondents were asked to consider the 12 skills included in the study and pick 4 whichthey thought are critical to their job. How many different ways are possible for an individualto make his/her selection?A. 48B. 495C. 20,736D. 11,88026) The respondents were asked to consider the 12 skills included in the study, and rank (as 1, 2,3, and 4) their top 4 choices. How many different ways are there that a person could makehis/her selection?A. 48B. 495C. 20,736D. 11,880For Questions 27 – 29, use the following information. Carry out calculations to 4 decimals.Laid-off workers who become entrepreneurs because they cannot find meaningful employmentwith another company are known as entrepreneurs by necessity. The Wall Street Journal reportedthat these entrepreneurs by necessity are less likely to grow into large businesses than areentrepreneurs by choice. The article states that 89% of the entrepreneurs in the United States areentrepreneurs by choice and 11% are entrepreneurs by necessity. Only 2% of entrepreneurs bynecessity expect their new business to employ 20 or more people within 5 years. But, 14% ofentrepreneurs by choice expect to employ at least 20 people within 5 years.27) What is the probability that a randomly selected entrepreneur believes his/her business willgrow to employ at least 20 people in 5 years?A. 0.1268B. 0.1246C. 0.0174D. 0.107828) What is the probability that a randomly selected individual is an entrepreneur by necessityand expects his/her business will grow to employ at least 20 people in 5 years?A. 0.0200B. 0.0022C. 0.1400D. 0.876529) An entrepreneur is selected at random who expects his/her new business will employ 20 ormore people within 5 years. What is the probability that this individual is an entrepreneur bychoice?8

A.B.C.D.

0.14000.12460.98260.1268

30) A state motor vehicle department would like to know how many license plate numbers areavailable if a license plate number consists of three letters (capital letters only) followed bythree numbers (0 through 9). The answer is:A. 18,940B. 28,497C. 17,576,000D. 18,920,020Use the following table and information to answer Questions 31 – 33. The table showsdiscrete probability distribution for the number of errors per a page of a medieval text.

31) What is the value of c (hint: the sum of probabilities equals 1.00)?A. Exactly equal to zeroB. Less than 1C. Greater than 1D. Cannot be computed since there are too many variables32) What is the mean of the discrete probability distributionA. Exactly equal to zeroB. Less than 1C. Greater than 1D. Cannot be computed since there are too many variables33) What is the variance of the discrete probability distribution (to four decimal places)?A. 1.1947B. 1.4275C. 7.6345D. 9.342834) The 3-year-survival rate for a certain group of cancer patients is known to be 0.60. What isthe probability (to four decimal places) that in a group of 10 patients, more than 5 patientssurvive at least 3 years (note: 3-year-survival is a binary outcome, and “success” is defined assurvival).A. .0011B. .2006C. .2508D. .633135) Customers arrive at a bank teller’s booth at a rate of 2 per minute. What is the probability (tofour decimal places) that 4 customers will arrive at the bank teller’s booth within the nextminute (assume a Poisson distribution)?A. .09029

B. .3324C. .6723D. 1.14336) Leaks occur along a pipeline at the mean rate of 0.5 leaks per mile. Assume Poissonproperties apply. What is the probability that a 3 mile stretch will have no leaks? (to fourdecimal places)A. 0.0498B. 0.6065C. 0.3679D. 0.223137) An insurance company has a call center that makes cold calls to individuals trying to sell lifeinsurance. The probability of making a sale is 0.10. Assume binomial properties apply. If anindividual in the center makes 20 calls, what is the probability they will make sales on morethan 4 calls?A. 0.9569B. 0.0431C. 0.2000D. 0.089838) A student has not been to class and must pass a 20 question true/false exam to continue in thecourse. The student will guess on every question and must get at least 14 correct to pass thetest. What is the probability that the student will pass the test?A. 0.0577B. 0.0739C. 0.0370D. 0.500039) Customers arrive at a bakery at an average rate of 10 customers per hour. What is theprobability that less than 5 customers will arrive in the next hour? Assume Poisson arrivals.A. 0.0378B. 0.0293C. 0.2500D. 0.112640) Customers arrive at a bakery at an average rate of 10 customers per hour. What is theprobability that exactly 20 customers will arrive in the next 2 hours? Arrivals are Poisson.A. 0.0019B. 0.1251C. 0.0888D. 0.5591For Questions 41 – 44, use Excel and the following information. According tobotttledwater.org, in 2012, the per capita consumption of bottled water in the USA was reportedas 30.8 gallons. Assume the per capita consumption of bottled water in the USA is normallydistributed with mean equal to 30.8 gallons and standard deviation equal to 10 gallons.10

41) What is the probability that someone in the United States consumed more than 32 gallons ofbottled water in 2012?A. 0.1294B. 0.4522C. 0.8268D. 0.547842) What is the probability that someone in the United States consumed between 10 and 20gallons of bottled water in 2012?A. 0.1213B. 0.0188C. 0.0177D. 0.234343) What is the probability that someone in the United States consumed less than10 gallons ofbottled water in 2012?A. 0.1213B. 0.0188C. 0.0177D. 0.018844) Ninety nine percent (99%) of the people in the United States consumed less than how manygallons of bottled water? Round off to one decimalA. 7.5B. 20.8C. 54.1D. 68.3For Questions 45 – 47, use the following information. Downloading times at a website isassumed to be uniformly distributed between 4.5 to 9.5 seconds.45) What is the probability that download time will take 9 to 13 seconds?A. 0.05B. 0.23C. 0.10D. 0.546) What is the probability that download time takes between 5 to 9 seconds?A. 0.6B. 0.8C. 0.43D. 0.847) What is the mean and standard deviation for download time?A. 7 and 1.44B. 2 and 2.35C. 9 and 1.47D. 5 and 3.0711

Use the following information to answer Questions 48 – 50.The time between unplanned shutdowns of a power plant has an exponential distribution with amean of 20 days.48) Find the probability that the time between two unplanned shutdowns is less than 14 daysA. 0.3347B. 0.1295C. 0.5034D. 0.786449) Find the probability that the time between two unplanned shutdowns is more than 21 daysA. 0.2947B. 0.65C. 0.5D. 0.349950) Find the probability that the time between two unplanned shutdowns is between 7 to 9 daysA. 0.0588B. 0.9210C. 0.0671D. 0.1017