Division of labor, economic growth, and development of monetary system marked a new era in human relations. People do not need to grow bread, feed animals, and take care about their babies at the same time any more. Working for some company or government means that at the end of the month person will get money to spend on the goods or services that involve labor of other people. Each time one goes to Walmart, Target, or Wegmans one expects that for certain sum of money he/she can buy certain products. It is not a secret that when buying a product person is supposed to get adequate amount of goods for the amount of money he/she pays.

US government controls the flow of goods that are consumed by the customers on the US market. Each corporation is obliged to insert information about the product company sells on its package such as the name of the product, ingredients, weight, etc. When conducting this research several questions were raised. Can person be sure that weight of the product corresponds the number written on its package? Do companies earn money from putting less amount of good that they are supposed to? As I am an ordinary consumer I want to be sure that I receive exactly the same amount for what I am paying for.

For this research “Tide” detergent 100 oz was taken in order to check the accuracy of the information written on its package. It is understood that Proctor and Gamble Company cannot control the exact amount of the liquid. Therefore, 100 oz is the approximate number and the quantity in each particular detergent may vary. 18 units of “Tide” detergents were bought to complete a research. The question is whether underweight of the product affects person’s budget or not. These are the results obtained after 18 items were weighed (in oz):

100.01   100.25   99.17   99.83   99.76   100.07   100.93   99.04   99.27

99.96    99.84   100.11   99.76   99.83   99.93   100.26   100.14   99.91

Using one-sample T-test (for small sample) I will try to analyze data written above and either prove that weight written on the package differs from the real one or get specific evidence that it is practically the same.

The Population Mean (m) = 100 oz (this is what is written on the product cover)

Sample size (n) = 18 items

Sample mean (`x) =  99.89 oz (this number is obtained through weighing 18 items)

S = √s² = 0.88

S²= 1/(n – 1) [ åx² – 1/n (åx)² ] = 0.775