Identify the equation of the least squares regression line that most closely matches the data set.
a
b
c
d

To determine which of the equations match the data set given, we need to do a trial and error experiment. First, we will try the first equation:

 y = 0.17x + 13.2 

substitute x = 2, if the value of y is 65 then this is a possible equation.

Do the same for the rest of the data points and the equation which fits all the points is the answer 

the law of definite proportions states samples of a compound will always contain the same proportion of elements by mass. in other words, a given compound will always contain the same elements in the same proportions by mass.the law of multiple proportions states when two elements combine with each other to form more than one compound, then the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.