In: Statistics and Probability
Show all calculation details by not using a calculator or Excel answers. Consider the data set: (7,11), (10,0), (13,-2).
A. Compute and interpret the coefficient of correlation.
B. Compute the least squares line for this data (no need to repeat computations from above).
Given data:
x | y |
7 | 11 |
10 | 0 |
13 | -2 |
A.) The correlation coefficient is claculated as,
Here, n=3
Hence, we get,
Therefore, r= -0.9286 . Here, negative sign represents that there is a negative correlation between X and Y. Also the magnitude 0.9286 is close to 1, hence there is a perfect negative correlation.
B.) To fit least square line, which is given as,
where a and b are calculated as,
Therefore, the least square line for this data :