How many tosses to get a head When we toss a penny,

Chapter 7, Problem 7.2

(choose chapter or problem)

How many tosses to get a head? When we toss a penny, experience shows that the probability (long-term proportion) of a head is close to 1/2. Suppose that we toss the penny repeatedly until we get a head. We want to know the probability that the fi rst head comes up in an odd number of tosses (1, 3, 5, and so on). To fi nd out, perform 20 trials, and keep a record of the number of tosses needed to get a head on each of your 20 trials. (a) From your results, estimate the probability of a head on the fi rst toss. What value should we expect this probability to have? (b) Use your results to estimate the probability that the fi rst head appears on an odd-numbered toss.