Samples Of Cast Aluminum Part Are Classified2

Samples of a cast aluminum part are classified on the basis of surface finish (in micro inches) and length measurements. The results of 100 parts are summarized as follows:
Length
Excellent Good
Surface excellent 80 2
Finish good 10 8
Let A denote the event that a sample has excellent surface finish, and let B denote the event that a sample has excellent length. Are events A and B independent?

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