Question

Consider the following sample data: x 11 13 27 22 30 y 28 26 25 20 16 Click here for the Excel Data File a. Calculate the covariance between the variables. (Negative value should be indicated by a minus sign. Round your intermediate calculations to at least 4 decimal places and final answer to 2 decimal places.) b. Calculate the correlation coefficient. (Round your intermediate calculations to 4 decimal places and final answer to 2 decimal places.

Answer 1

	n=	5.0000
	X̅=ΣX/n	20.600
	Y̅=ΣY/n	23.000
	sx=(√(Σx2-(Σx)2/n)/(n-1))=	8.385
	sy=(√(Σy2-(Σy)2/n)/(n-1))=	4.899
	Cov=sxy=(ΣXY-(ΣXΣY)/n)/(n-1)=	-32.0000
	r=Cov/(Sx*Sy)=	-0.7791

a) covariance between the variables = -32.0000

b) correlation coefficient =-0.78