can any one answer?

Question

f all the points in a scatter diagram lie on the least squares regression line, then the coefficient of correlation must be:
Question 2 answers
1.0
-1.0
either 1.0 or -1.0
0.0

Answer 1

The correlation coefficient describes the closeness of the points on a scatter diagram to the least squares regression line. If the points all lie on the least square regresion line and the line has a positive gradient the correlation coefficient is 1. Similarly if the points all lie on the line and the line has a negative gradient the
coefficient is -1.

So the best answer is:
c) either 1.0 or -1.0

Answer 2

The answer is "Either 1.0 or -1.0".

If all the points in the scatter diagram are on the least squares line, then, they exhibit a perfect linear correlation between them, so their co-efficient is either +1, or -1, depending on the slope of the regression line.

trust this helps... :-)

Answer 3

1 or -1

The magnitude of this coefficient indicates the linearty of the data: as it goes up as the data points become more linear.

The sign indicates the slope of the line.