# Data Mining Assignment

Autor: Norsyuhada Johan • October 7, 2015 • Exam • 686 Words (3 Pages) • 756 Views

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__ (QMT758)__

ASSIGNMENT 1

Name: Norsyuhada Binti Johan

Matrix No: 2014260284

Lecturer’s Name: Halilah Haron (Assoc. Prof.)

Question 4.28

An auditor detects that a certain firm is regularly overstating the dollar amounts of inventories because of delays in recording withdrawals. The auditor wants to estimate the total overstated amount on 1000 listed items by obtaining exact (audited) inventory amounts on a random sample of 15 items and comparing these exact figures with the recorded amounts. The data for the sampled items are as shown in the following table. Estimate the total overstated amount on the 1000 items and place a bound on the error of estimation.

Item No | Audited amount ($) | Recorded amount ($) | Overstatement (diff, $) |

1 | 175 | 210 | 35 |

2 | 295 | 305 | 10 |

3 | 68 | 91 | 23 |

4 | 74 | 82 | 8 |

5 | 128 | 140 | 12 |

6 | 241 | 250 | 9 |

7 | 362 | 384 | 22 |

8 | 72 | 80 | 8 |

9 | 59 | 82 | 23 |

10 | 112 | 140 | 28 |

11 | 118 | 124 | 6 |

12 | 210 | 230 | 20 |

13 | 240 | 260 | 20 |

14 | 123 | 147 | 24 |

15 | 96 | 108 | 12 |

Answer:

By using scientific calculator, get the value of and [pic 1][pic 2]

n=15

N=1000

=17.333[pic 3]

=75.238[pic 4]

τ = Total overstated amount

[pic 5]

[pic 6]

[pic 7]

A 95% for τ

= [pic 8]

= [pic 9]

= [pic 10]

Question 4.38

What is the average body temperature under normal conditions? Is it the same for both men and women? Medical researchers interested in this question collected data from a large number of men and women. Two random samples from that data, each of size 10, are recorded. Estimate the mean body temperature of men with a two standard deviation margin of error.

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