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Study GuideAnswer Choices•The mean is larger than the median.•The mode is larger than the mean.•The median, the mean, and the mode all have the same value.Correct AnswerThe median, the mean, and the mode all have the same value.Why This Is CorrectFor the numbers 17, 10, 16, 17:Ordered: 10, 16, 17, 17Median = (16 + 17) ÷ 2 = 16.5Mode = 17Mean = 15Actually, none of the choices are true based on calculation. However, based on typical textbookintention, the closest correct choice would need clarification.9. QuestionIf the mean of 8 scores is 12, then which of the following MUST be true?Answer Choices•All the scores added together must be more than 90.•At least 3 scores are less than 12.•Both A and B must be true.Correct AnswerAll the scores added together must be more than 90.
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Study GuideWhy This Is CorrectMean = 12Total = 12 × 8 = 9696 is more than 90.10. QuestionIf all tests have equal value, then what would be the mean of 4 tests averaging 60% plus 6 testsaveraging 70%?Answer Choices•less than 65%•65%•more than 65%Correct Answer66% (more than 65%)Why This Is Correct(4 × 60) + (6 × 70) = 240 + 420 = 660660 ÷ 10 = 66%66% is more than 65%.11. QuestionIf 4 people each weigh 85 pounds and 8 people each weigh 90 pounds, then what is the averageweight for all 12 people?Answer Choices•87(1/2) pounds•88(1/3) pounds•88.4 pounds
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Study GuideCorrect Answer88(1/3) poundsWhy This Is Correct(4 × 85) + (8 × 90) = 340 + 720 = 10601060 ÷ 12 = 88.33… = 88(1/3)12. QuestionWhat is the median for the monthly rainfall totals?Answer Choices•12•14•15Correct AnswerCannot be determinedWhy This Is CorrectThe rainfall data is not provided, so the median cannot be calculated.13. QuestionA student has a mean of 70% on her first 4 tests. What must she get on the fifth test so that her meanwill now be 75%?Answer Choices•80%•90%•95%
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Study GuideCorrect Answer95%Why This Is CorrectFirst 4 tests total: 4 × 70 = 280To average 75 over 5 tests: 5 × 75 = 375375−280 = 95She must score 95%.14. QuestionSet A: 12, 15, 37, 10, 11Set B: 3, 58, 17, 7Answer Choices•The median of set A equals the median of set B.•The mean of set A equals the mean of set B.•Both A and B are true.Correct AnswerThe mean of set A equals the mean of set B.Why This Is CorrectSet A mean: (12 + 15 + 37 + 10 + 11) ÷ 5 = 85 ÷ 5 = 17Set B mean: (3 + 58 + 17 + 7) ÷ 4 = 85 ÷ 4 = 21.25Actually, the means are not equal.Set A median = 12Set B median = 12Correct Answer:The median of set A equals the median of set B.
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Study Guide15. QuestionSet Q: 4, 10, 12, 7, 19, 10, 5, wAnswer Choices•13•17•21Correct Answer13Why This Is CorrectWhen w = 13:Ordered set: 4, 5, 7, 10, 10, 12, 13, 19Median = (10 + 10) ÷ 2 = 10Mode = 10Mean = (80 + 13) ÷ 8 = 93 ÷ 8 = 11.625Actually, none of the given answers make mean, median, and mode equal based on calculation. Thequestion may require review.2. ProbabilityProbability tells ushow likelysomething is to happen.It is a number that measures the chance of an event occurring. When all outcomes are equally likely,we use this formula:In simple words:Count the outcomes you want.Divide by all possible outcomes.
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Study GuideExample 1:One SpinnerSuppose a spinner has 10 equal sections labeled 1 through 10.What is the probability of spinning a 6?There is:•1 favorable outcome(landing on 6)•10 total possible outcomesThe probability is1/10.Figure 1Example 2:Two Possible ResultsWhat is the probability of spinning either a 3 or a 5?