Answer to Question #40448 in Statistics and Probability for Dale

Question

Consider the random experiment of rolling a fair die.
a.) Let X be the number of tosses needed before obtaining a 6. Find the mass function and expected value of X.
b.) Let X be the number of tosses needed before obtaining 3 sixes. Find the mass function and expected value of X.
c.) Let X be the number of sixes obtained in 5 rolls of the die. Find the mass function and expected value of X.