1. Which of the following is a method of data collection that is used in surveys? a. telephone b. Mail c. the Internet d. all of the above 2. All of the following are examples of an observation study EXCEPT: a. a mystery shopper pretending to be a customer in a McDonald’s outlet b. a cable laid across the street that records the number of cars that pass a certain intersection c. determining how long employees spend taking breaks to smoke cigarettes d. a consumer responding to a questionnaire about
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* Columns correspond to Variables * Rows correspond to individuals * Rows are often called observations or cases * The number of rows is traditionally denoted by n * In the bar chart the height of each bar is proportional to the count (or percent) in each category * In the pie chart the area of each piece is proportional to the percent of individuals in each category * Pareto chart when the categories are sorted by frequency * Pie charts are less useful than bar charts
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70 words per minute‚ it’s a pretty safe bet that it’s not John. That would be a test based simply on raw speed uncorrected for errors. It’s only a one-way test‚ as it’s always possible for people to go slower than normal‚ but it’s unusual or impossible for them to go twice their normal speed. Or‚ it may be that the mystery user at the keyboard and John both type at 50 words per minute; but John never really learned the numbers‚ and always has to slow down an extra half-second whenever a number has
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discovery phase of the lawsuit‚ when both side submit all of the information they have to each other‚ the insurance company hired an independent CPA firm to calculate the GPF. To determine fraud‚ our group had to find the probability that a standard normal random variable exceeded the GPF samples given to us. We used the entire data set of 3‚005 invoices as the population‚
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PERT is a widely used method for planning and coordinating large-scale projects. To obtain: • A graphical display of project activities. • An estimate of how long the project will take. • An indication of which activities are the most critical to timely project completion. • An indication of how long any activity can be delayed without delaying the project. The Network Diagram Network (precedence) diagram -Diagram of project activities that shows sequential relationships by the use of
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QNT/351 1) The main purpose of descriptive statistics is to A. summarize data in a useful and informative manner B. make inferences about a population C. determine if the data adequately represents the population D. gather or collect data 2) The general process of gathering‚ organizing‚ summarizing‚ analyzing‚ and interpreting data is called A. statistics B. descriptive statistics C. inferential statistics D. levels of measurement 3) The performance of personal and business investments
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mean is called the 9. Suppose a population consisted of 20 items. How many different sample of n = 3 are possible? 10. A point estimate is 11. We wish to develop a confidence interval for the population mean. The population follows the normal distribution‚ the standard deviation of the population is 3‚ and we have a sample of 10 observations. We decide to use the 90 percent level of confidence. The appropriate value of to represent the level of confidence is 12. A confidence interval
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0.07 0.06 p(x) 0.05 0.04 0.03 0.02 0.01 0 -5 -4 -3 -2 -1 0 x(t) Basic Statistical properties Marco Tarabini 1 2 3 4 5 Introduction 2 If a physical phenomenon of interest is random‚ then each time history measurement x(t) of that phenomenon represents a unique set of circumstances which is not Iikely to be repeated in other independent measurements of that same phenomenon. Hence‚ to completely define all properties of the phenomenon‚ it
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standard deviation of 0.02 centimeter. All components deviating by more than 0.05 centimeter from the mean must be rejected. What percentage of parts must be rejected? Assume a normal distribution. 3. Assume that the number of cases sold per week in December by a large group of beverage salesmen is quite close to normal distribution with a mean of 684 and a standard deviation of 60. a. Given that the top 16% of the salesmen receive bonuses‚ how many cases must a salesman sell in order to receive
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and +1. D) has none of the above properties. 5. For a continuous random variable‚ the total area beneath the probability distribution curve will be greater than 0 but less than 1. A) True False 6. The standardized normal distribution always has a mean of zero and a standard deviation of one. True A) False 7. Excel’s RAND() function produces random numbers that are uniformly distributed from 0 to 1. The standard deviation of this distribution
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