Exploring Measurement in the Food Industry

Our task for this lab was to collect mass information about various bags of Cheetos and use our data to determine the accuracy and precision of the bags. The purpose of this lab was to answer the guiding question, "Do you get what you pay for?". In this lab we used accuracy and precision to determine whether or not you get your money's worth when buying a small bag of Cheetos. On the packaging the bag states it's net weight is 28.3 grams. We used four different Cheetos bags to gather information. The first step was to find accuracy. Accuracy is defined as the net weight of 28.3g +/- .10g. We weighed the full bags of Cheetos separately and recorded the results, this is the gross weight. We then emptied the contents of the bags and weighed the packaging and recorded those results, this is the tare weight. After finding the gross and tare weight we then subtracted the tare weight from the gross weight and found our difference. The results are below. (G= Gross, T=Tare, D=Difference)
Bag 1- G = 30.10, T = 1.43, D = 28.67
Bag 2- G = 30.03, T = 1.46, D = 28.57
Bag 3- G = 29.95, T = 1.50, D = 28.45
Bag 4- G = 30.41, T = 1.50, D = 29.26
Based upon the results these bags do not fit within accuracy. The next step was to find the precision of the bags. Precision is defined as variance ≤.20g. in order to find it you must subtract your maximum value by the minimum value. So we subtracted 29.26 from 28.45 which equaled .81g which is significantly larger than the .20g that is defined as precision. Based upon that we can see that the bags are not precise. Our claim based upon the four Cheetos bags we tested was, You do not get what you pay for, you receive more than what is advertised. Our evidence for this claim is that when weighed, the bags don't not fall between the parameters defined for accuracy nor precision. Our justification is that when purchasing a bag of Cheetos you expect there to be the advertised 28.3g of chips. In reality you do receive more than what you pay for. So depending on your personal opinion you could argue that you do receive what you pay for and also additional Cheetos. However I feel that you do not receive what you pay for because the bags do not fall within accuracy or precision.