9.3 Random digits. The table of random digits (Table B) was produced by a random mecha nism that gives each digit probability 0.1 of being a 0. So random digits can illustrate the idea of probability.

(a) Count the number of Os in each of the first 5 rows of Table B. Each row has 40 digits.

What are the proportions of Os in each of the first 5 rows? You see that proportions in just 40 trials need not be very close to the probability 0.1.

(b) Combine your counts: how many Os ate there among the 200 digits in the first 5 rows of the table? Of course, 200 trials is not the long run, but already the proportion is coming closer to the probability 0.1.