Question

The following 12 data pairs relate y, the percentage yield of a labora- tory experiment, to x, the temperature at which the experiment was conducted. 1 100 110 120 125 130 140 45 51 54 53 59 63 150 69 8 160 74 9 17078 1018086 190 89 12 200 94 4 5 6 (a) Represent these data in a scatter diagram. (b) Do you think a simple linear regression model would be appropri- ate for describing the relationship between percentage yield and temperature?

Answer 1

a) Scatter Diagram  

b) As can be seen from the above scatter diagram, the representation is very close to a straight line  
Hence, a simple linear regression can be appropriate for describing the relationship between percentage  
yield and temperature.  
  
Using Excel tool Data->Data Analysis -> Regression, we get the regression line as   

Scatter Diagram 100 90 80 70 60 50 40 30 20 10 0 0 50 100 150 200 250 Temperature Percentage Yield

	Coefficients
Yield	-6.1242
Temperature	0.5006

Thus, regression line is   
Yield = 0.5006 * Temperature - 6.1242  

OR

Y = 0.5006 x - 6.1242