Application of Statistical Concepts in the Determination of Weight Variation in Samples

APPLICATION OF STATISTICAL CONCEPTS IN THE DETERMINATION OF WEIGHT VARIATION IN SAMPLES

J. N. CHUA CHAM

1NATIONAL INSTITUTE OF MOLECULAR BIOLOGY AND BIOTECHNOLOGY

UNIVERSITY OF THE PHILIPPINES, DILIMAN, QUEZON CITY 1101, PHILIPPINES

DATE SUBMITTED: 21 NOVEMBER 2013

DATE PERFORMED: 14 NOVEMBER 2013

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ABSTRACT

The purpose of this experiment was to train the students on the proper way of handling objects and instruments in the laboratory. It also served as an exercise for the students in computing for and using statistical formula and data for future use. The students were able to apply the “Weighing by Difference” method of using the analytical balance which is a better method when compared to individually weighing the coins as the latter takes more time to do. After doing so, the students got the individual weights of the coins and using Dixon’s Q-test, eliminated outliers from the data gathered. Upon rejecting all values which did not pass Dixon’s Q-test, the students looked for the mean, standard deviation, relative standard deviation, range, relative range and confidence limits at 95% confidence level. One outlier was found for the data set 1 but none for the data set 2.

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RESULTS AND DISCUSSION

The results are as follows (table 1):

Table 1. Weight of samples

Sample No. | Weight, g |

1 | 3.6920 |

2 | 3.5850 |

3 | 3.6190 |

4 | 3.6013 |

5 | 3.5885 |

6 | 3.6176 |

7 | 3.5299 |

8 | 3.5668 |

9 | 3.5726 |

10 | 3.6161 |

The weights were taken using an analytical balance and a method called: “Weighing by Difference”. In this method, all the coins are placed on a watch glass and put into the analytical balance and tare was pressed. Once the reading zeroed out, one coin was taken out using tweezers. The reading on the screen should have been...