Question

From a sample of 15 observations, the following results were obtained:

∑Y_i = 1,800                              

∑X_i = 2,000

∑Y_iX_i = 305,000

∑X_i² = 350,000

∑Y_i² = 310,000

With coefficient of correlation r = 0.734. But on rechecking these calculations it was found that three pairs of observations were recorded incorrectly.

Incorrect Y	Incorrect X		Correct Y	Correct X
70	100		50	80
120	200	Instead of	140	180
150	240		160	250

Obtain the correct r.

Answer 1