Statistics

Record your answers and work.

Problem Number | Solution |

1(25 pts) | Answers: (a) True : A zero variance identical that there is no variation thus identical data values (b) False (c) True: for a normal distribution, mean, median and mode are equal and they fall along the symmetry of the curvefalse (d) (e) true Work for (a), (b), (c), (d) and (e): |

2(5 pts) | Answer: Study Time (in hours) | Frequency | Relative Frequency |

0.0 – 4.9 | 5 | 　0.05 |

5.0 - 9.9 | 13 | 　0.18 |

10.0 - 14.9 | 4 | 　0.22 |

15.0 -19.9 | 42 | 0.64 |

20.0 –24.9 | 36 | 　1.00 |

Total | 100 | 　 |

Work:5/100 = 0.05(5+13)/100= 0.180.22-0.18-0.05=0.04x100=45+13+4+42=64/100=0.64100- (5+13+4+42)=36 |

3(5 pts) | Answer: 15.0 -19.9Work: 15 lies within this class |

4(5 pts) | Answer: 15.0 – 19.9Work: median which is 0.5 in included in the relative frequency of 0.64 which is in this class |

5(5 pts) | Answer: Negative skewWork: when plotted , the tail is to the left; the median is in the class 15.0 -19.9 which is on more of right than left thus a negative skews |

6(5 pts) | Answer: 20Work: table of possible outcomes for two die throws; you count the events where the first throw is a multiple of three and the second outcome is greater than four avoid repeating yourself (in bold) throws | 1 | 2 | 3 | 4 | 5 | 6 |

1 | 1,1 | 1,2 | 1,3 | 1,4 | 1,5 | 1,6 |

2 | 2,1 | 2,3 | 2,4 | 2,5 | 2,6 | 2,7 |

3 | 3,1 | 3,2 | 3,3 | 3,4 | 3,5 | 3,6 |

4 | 4,1 | 4,2 | 4,3 | 4,5 | 4,6 | 4,7 |

5 | 5,1 | 5,2 | 5,3 | 5,4 | 5,6 | 5,7 |

6 | 6,1 | 6,2 | 6,3 | 6,4 | 6,5 | 6,7 |

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7(10 pts) | Answer: 4/20 = 1/5Work:You count the events that has multiple of three as the first outcome and the second throw is greater than four |

8(5 pts) | Answer: A and B are independent Work:since the first outcome does not influence the outcome of second throw |

9(5 pts) | Answer: both quizzes has same rangeWork: | Lower quartile | Upper quartile | range |

Quiz 1 | 40 | 95 | 55 |...