Coefficient of Correlation?

Hi,

help me to solve this..

X=2,4,5,6,8,11

Y=18,12,10,8,7,5

(i)Calculate coefficient of correlation, using Excel function, for the above data.

What type of relationship is found between the variables X and Y?

(ii) Construct a Scatter diagram for the above Data.

(iii) Now subtract 10 from values of X and divide by 5.Also subtracts 4from values of Y and divide by 2.

Now again calculate coefficient of correlation .And give reason why answer do or do not match.

Thnx