In: Statistics and Probability
A data set is given below. (a) Draw a scatter diagram. Comment on the type of relation that appears to exist between x and y. (b) Given that x̅ = 3.8333, Sx = 2.4014 , ȳ equals = 3.7333 3., Sy = 1.8381, and r = -0.9545 , determine the least-squares regression line.
(c) Graph the least-squares regression line on the scatter diagram drawn in part
x y
0 5.9
2 5.7
4 4.3
5 2.8
6 1.7
6 2
(a) Choose the correct graph below.
A.
There appears to be
a linear, negative
relationship.
(b)ŷ __?__x+( __?__)
(Round to three decimal places as needed.)
(a).
A) The following scatter plot is obtained based on the data provided:
There appears to be a negative linear relationship.
B)
The independent variable is X, and the dependent variable is Y. In order to compute the regression coefficients, the following table needs to be used:
X | Y | X*Y | X2 | Y2 | |
0 | 5.9 | 0 | 0 | 34.81 | |
2 | 5.7 | 11.4 | 4 | 32.49 | |
4 | 4.3 | 17.2 | 16 | 18.49 | |
5 | 2.8 | 14 | 25 | 7.84 | |
6 | 1.7 | 10.2 | 36 | 2.89 | |
6 | 2 | 12 | 36 | 4 | |
Sum = | 23 | 22.4 | 64.8 | 117 | 100.52 |
Based on the above table, the following is calculated:
Therefore, based on the above calculations, the regression coefficients (the slope m, and the y-intercept n) are obtained as follows:
Therefore, we find that the regression equation is:
Y = 6.5341 - 0.7306 * X
Graphically:
Let me know in comments if anything is not clear. Will reply ASAP. Please do upvote if satisfied.