im not sure how to calculate these three questions -- please provide me with a step by step solution as to how to complete these. thanks.

Use the information below to answer the next three questions Security Standard deviation Variance Ford 25 625 GM BE 1 , 225 index Sap 500 30 900 Covariance Ford with the STEP 600 GM with the Sap 612.50 Ford with GM 845 2 . Use the information above to calculate the correlation between Ford and GM a ) 58 % 6 72 % C ) 80% ) 970 3 . Use the information above to calculate the correlation between Ford and index a ) 58 % b ) 72 % ( ) 80 % d ) 97 % 4 . Use the information above to calculate the correlation between GM and index 2 ) 58 % b ) 72 % 0 ) 80 % 2 97 %