Experiment 1 Application of Statistical Concepts in the Determination of Weight Variation in Samples
Experiment 1: APPLICATION OF STATISTICAL CONCEPTS IN THE DETERMINATION OF WEIGHT VARIATION IN SAMPLES
LEE, Hyun Sik
Chem 26.1 WFV/WFQR1
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Nov. 23, 2012
A skillful researcher aims to end his study with a precise and accurate result. Precision refers to the closeness of the values when some quantity is measured several times; while accuracy refers to the closeness of the values to the true value. The tool he utilizes to prevent errors in precision and accuracy is called statistics. In order to become familiar to this tactic, the experiment aims to help the researchers become used to the concepts of statistical analysis by accurately measuring the weights of ten (10) Philippine 25-centavo coins using the analytical balance, via the “weighing by difference” method. Then, the obtained data divided into two groups and are manipulated to give statistical significance, by performing the Dixon’s Q-test, and solving for the mean, standard deviation, relative standard deviation, range, relative range, and confidence limit—all at 95% confidence level. Finally, the results are analyzed between the two data sets in order to determine the reliability and use of each statistical function.
RESULTS AND DISCUSSION
This simple experiment only involved the weighing of ten 25-centavo coins that are circulating at the time of the experiment. In order to practice calculating for and validating accuracy and precision of the results, the coins were chosen randomly and without any restrictions. This would give a random set of data which would be useful, as a statistical data is best given in a case with multiple random samples. Following the directions in the Analytical Chemistry Laboratory Manual, the coins were placed on a watch glass, using forceps to ensure stability. Each was weighed according to the “weighing by difference” method.
The weighing by difference method is used when a series of samples of similar size are weighed
LEE, Hyun Sik
Chem 26.1 WFV/WFQR1
-------------------------------------------------
Nov. 23, 2012
A skillful researcher aims to end his study with a precise and accurate result. Precision refers to the closeness of the values when some quantity is measured several times; while accuracy refers to the closeness of the values to the true value. The tool he utilizes to prevent errors in precision and accuracy is called statistics. In order to become familiar to this tactic, the experiment aims to help the researchers become used to the concepts of statistical analysis by accurately measuring the weights of ten (10) Philippine 25-centavo coins using the analytical balance, via the “weighing by difference” method. Then, the obtained data divided into two groups and are manipulated to give statistical significance, by performing the Dixon’s Q-test, and solving for the mean, standard deviation, relative standard deviation, range, relative range, and confidence limit—all at 95% confidence level. Finally, the results are analyzed between the two data sets in order to determine the reliability and use of each statistical function.
RESULTS AND DISCUSSION
This simple experiment only involved the weighing of ten 25-centavo coins that are circulating at the time of the experiment. In order to practice calculating for and validating accuracy and precision of the results, the coins were chosen randomly and without any restrictions. This would give a random set of data which would be useful, as a statistical data is best given in a case with multiple random samples. Following the directions in the Analytical Chemistry Laboratory Manual, the coins were placed on a watch glass, using forceps to ensure stability. Each was weighed according to the “weighing by difference” method.
The weighing by difference method is used when a series of samples of similar size are weighed
References: Silberberg, M. S. (2010). Principles of general chemistry (2nd ed.). New York, NY: McGraw-Hill Jeffery, G http://www.bsp.gov.ph/bspnotes/banknotes_coin.asp. Accessed Nov. 21, 2012. s= 3.6427-3.61912+3.5611-3.61912+3.6206-3.61912+3.6104-3.61912+3.6921-3.61912+(3.7531-3.6191)2+(3.5732-3.6191)2+(3.5593-3.6191)2+(3.6095-3.6191)2+(3.5687-3.6191)29 =0.06289 confidence limit=3.6467± (2.57)(0.06742)6=3.6467 ±0.07074 3.6467-0.07074=3.5760 Data Set 2 confidence limit=3.6191± (2.26)(0.06289)10=3.6191 ±0.04495