Question

Given the following sample observations, draw a scatter diagram on a separate piece of paper. (Round your answers to 3 decimal places.) X: -6 -17 12 3 17 Y: 52 248 151 4 341

The coefficient of correlation is .

Does the relationship between the variables appear to be linear?

Try squaring the X- variable and then determine the correlation coefficient. .

Answer 1

This is a simple problem related to

1. Tracing a scatter plot

2. Determining its coefficient of correlation and

3. Determining the coefficient of correlation for X square.

We noted down the values of X and Y in the table below and drew its corresponding scatter plot in excel ( Excel -> insert-> scatter plot)

X	Y
6	52
17	248
12	151
3	4
17	341

Scatter plot with the linear regression equation and R² value.

Calculation of coefficent of correlation

Thus the coefficent of correlation is found to be 0.963 or 96.3 %

Now to find the coefficient of correlation when the X values are squared keeping Y value as same

Thus the coefficent of correlation in this case will be equal to 0.97 or 97 % (it has increased marginally)