1. A researcher wishes to see if there is a relationship between the number of calories a sandwich has and the sodium content of the sandwich. Several different types of sandwiches are used. The data follow (Source: Consumer Reports 60, no. 9, September 1995) Calories, x 419 419 386 240 354 231 174 Sodium (mg), y 645 1202 066 1139 787 2. A researcher wishes to determine if there is a relationship between the energy efficiency rating (EER) of an air conditioner and its cost. The EER is determined by the Appliance Manufacturers' Association (Source: Consumer Reports 60, no.6, June 1995, p.406). The data follow EER, X 9.5 10.0 10.0 10.0 10.3 9.1 8.6 Cost ()), y 370 360 400 400 420 350 310 3. An educator wants to see the relationship between a student's score on a test and his or her grade point average. The data obtained from the sample follow. Test score, X 98 105 100 106 95 116 112 GPA, y 2.6 2.1 2.3 2.0 2.4 1.7 1.9 4. An English instructor is interested in finding the strength of a relationship between the final exam grades of students enrolled in English 1 and English 2 classes. The data are given below in percentages. Check your answer in calculator. English 1, x | 83 97 80 95 73 78 91 86 English 2, y 95 83 97 06 80 Regression Analysis If you want to come up with an equation relating the variables X and Y, we call this as regression analysis. Regression is a statistical method used to describe the nature of the relationship between variables, that is, positive or negative, linear or nonlinear. If the relationship between X and Y can be described by a straight line equation, it is called simple regression analysis. The equation can be estimated by the model =a+ bx where b =