The coefficient of correlation between variables y and x is 0.80 ...

[Arii_bell]

The coefficient of correlation between variables y and x is 0.80 . Calculate and interpret the value of the coefficient of determination.

Question 2

For a given value of x, which will be wider, a 90 confidence interval or a 90 prediction interval? Explain

[uniquea123]

Answer to Question 1

The coefficient of determination is 0.64 (or the coefficient of correlation squared). This means that 64 of the variation in y and is explained by x.

Answer to Question 2

For a given value of s, the prediction interval will always be wider than the confidence interval. The confidence interval is concerned with the mean value of y only; the prediction interval is concerned with all of the possible values of y.