Math 1342 Test 2 Review. Total number of students = = Students between the age of 26 and 35 = = 2012

Transcription

1 Math 1342 Test 2 Review 4) Total number of students = = 6397 Students between the age of 26 and 35 = = 2012 Students who are NOT between the age of 26 and 35 = = 4385 Therefore, the number of outcomes the comprise the event (not A) = ) Total number of students = = 6397 Students under the age of 31 = = 5363 Students NOT under the age of 31 = = 1084 Therefore, the number of outcomes the comprise the event (not A) = 1084

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4 Computational tool at

5 Not: Histogram was constructed with tool at

6 14) Since the professor gives each student 10 minutes, "To wait no longer than 20 minutes" means that there must be no more than 2 students already waiting to see the professor. Therefore, P("Student has to wait no longer than 20 minutes") = P("No more than 2 students are already waiting") = P(X 2) = P(X = 0) + P(X=1) + P(X=2) = = ) Since the professor gives each student 10 minutes, "To wait at least 30 minutes" means that there must be at least 3 students already waiting to see the professor. Therefore, P("Student has to wait at least 30 minutes ") = P(at least 3 students are already waiting to see the professor) = P(X 3) = P(X = 3) + P(X=4) + P(X=5) = = ) "everyone will have a place to sit at our next party" means that number of people at the party must be less than or equal to 8. Therefore, P( "everyone will have a place to sit at our next party") = P(number of people at the party must less than or equal to 8) = P(X 8) = P(X = 5) + P(X + 6) + P(X = 7) + P(X = 8) = = 0.45

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12 26) Computational Tool at

13 27) Computational Tool at Therefore, area to the left of 1.13 =

14 28) Computational Tool at

15 29) Computational Tool at

16 30) Computational Tool at

17 31) Computational Tool at

18 32) Computational Tool at Therefore, z-score = 1.75

19 33) Computational Tool at Therefore, z-score = -0.25

20 34) Computational Tool at Therefore, z-score = -1.34

21 35) Computational Tool at P(X < 53) means find area to the left of a score of 53. Therefore, P(X < 53) = area to the left of a score of 53 = = 4.01%

22 36) Computational Tool at P(X > 16.1) means find area to the right of a score of Therefore, P(X > 16.1) = area to the right of a score of 16.1 = = 15.87%

23 37) Computational Tool at P(19.7 < X < 25.3) means find area between the scores of 19.7 and Therefore, P(19.7 < X < 25.3) = area between the scores of 19.7 and 25.3 = = 74.6%

24 38) Q1 mean first quartile or 25th percentile. To find the first quartile Q1 means finding a score such that 25% of all observations are less than this score. Hence, we need to find score corresponding to a left-tailed area of 25% or 0.25.

25 39) Q3 mean third quartile or 75th percentile. To find the third quartile Q3 means finding a score such that 75% of all observations are less than this score. Hence, we need to find score corresponding to a left-tailed area of 75% or 0.75.

26 40) Q1 mean first quartile or 25th percentile. To find the first quartile Q1 means finding a score such that 25% of all observations are less than this score. Hence, we need to find score corresponding to a left-tailed area of 25% or 0.25.

27 Hence, we need to find score corresponding to a left-tailed area of 20% or 0.20.

28 42) Q3 mean third quartile or 75th percentile. To find the third quartile Q3 means finding a score such that 75% of all observations are less than this score. Hence, we need to find score corresponding to a left-tailed area of 75% or 0.75.

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