Which of the following is a model for obtaining "heads" using a biased coin (with probability of "heads" being 0.8)? (" 1 " is for "heads", " 0 " is for "tails") Hint: you can try this out in Excel = RAND ( ) * 0.8 = IF( RAND ( ) < 0.2, 0, 1) = IF (PROBABILITY = 0.8, 1, 0 ) = IF ( RAND ( ) < 0.8, 0, 1)