An exam consists of 20 multiple-choice questions. Each question has five possible answers and all questions carry equal weight. Mary has not studied for the exam and will be picking her answers at random. What is the probability that Mary will get a score of at least 30% on this exam? n=20‚ p=0.20 P(X≥6) (0.30)(20)=6 Distribution Plot Binomial‚ n=20‚ p=0.2 0.25 Probability 0.20 0.15 0.10 0.05 0.1958 0.00 0 P(X≥6)=0.196 X 6 If 40% is the lowest passing
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CHAPTER 12: TESTS FOR TWO OR MORE SAMPLES WITH CATEGORICAL DATA 1. When testing for independence in a contingency table with 3 rows and 4 columns‚ there are ________ degrees of freedom. a) 5 b) 6 c) 7 d) 12 ANSWER: b TYPE: MC DIFFICULTY: Easy KEYWORDS: chi-square test of independence‚ degrees of freedom 2. If we use the [pic] method of analysis to test for the differences among 4 proportions‚ the degrees of freedom are equal to:
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Last name: First name: Student #: STA 304H1 F/1003H F SUMMER 2009‚ First Test‚ May 28 (20%) Duration: 50min. Allowed: hand-calculator‚ aid-sheet‚ one side‚ with theoretical formulas and definitions only. [25] 1) A marketing analyst is asked to study the buying habits of shoppers at a national chain store (e.g. Sears). Suppose there are 150 stores around the country. (a) Describe the population of interest. (b) Describe in short a realistic sampling procedure for obtaining a representative
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5.23 Let x be a normally distributed random variable having mean = 30 and standard deviation . Find the z value for each of the following observed values of x: In each case‚ explain what the s value tells us about how the observed value of x compares to the mean 5.29 Weekly demand at a grocery store for a brand of breakfast cereal is normally distributed with a mean of 800 boxes and a standard deviation of 75 boxes‚ a. What is the .probability that weekly demand is (1) 959 boxes or less? (2) More
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1. A recent issue of Fortune Magazine reported that the following companies had the lowest sales per employee among the Fortune 500 companies. [20 Marks] | |Company |Sales per Employee ($1000s) |Sales Rank | | |Seagate Technology |$42.20 |285 | | |SSMC | 42.19
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Executive Overview‚ Part I The management staff at a hotel located in a popular Caribbean resort area is engaged in planning activities for the next year. Fundamental to any plans made will be the expected occupancy rate of the hotel. The management staff has extracted quarterly occupancy rates for the past 5 years from the hotel records to forecast the occupancy rates for quarters 1‚ 2‚ 3 and 4 of next year. Observing that this is a time series problem‚ we first generated a time series plot of
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Random Sample: each member of the population has the same chance of being selected Representative Sample: characteristics should represent those of the target population without bias Observational Study: no intervention by the investigator‚ no treatment imposed Experimental Study: investigator has some control over the determinant Variables: Categorical – each observation falls into a finite number of groups Nominal: named variables with no implied order e.g. personality type Ordinal:
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Harrisburg High school was bully central. 75% of all students were either being bullied or doing the bullying‚ unaware of the damage being done. Students who bully are some of the leading causes of death due to suicide by those bullied. The effects on teenagers are possible suicide and low self-esteem‚ one possible solution would be counseling for those who bully. To begin‚ an effect of bullying on teenagers is possible suicide. Kayla Marcella would be 19 years old this year .Marcella committed
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Term Random Variable Definition A variable that takes on different numerical values based on chance Term Discrete Random Variable Definition A random variable that can only assume a finite number of values or an infinite sequence of values such as 0‚1‚2‚3.... Term Continuous Random Variables Definition Random variables that can assume any vallue in an interval. Term Expected Value Definition The mean of a probability distribution. the average value when the experiment
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GMB 713 PROBLEM SET NO. 2 PROBLEM SOLVING: Solve the following problems. Show all pertinent solutions. 1. A car battery dealer is trying to determine which of the brands of car battery he is selling has a longer life span. He conducted an investigation by interview his customers and was able to get the following results: Brand X Brand Y Mean life span 4.5 years 4.9 years Standard deviation
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