The experimental probability that the next customer buys a red notebook with 150 pages is 33/200.
An experimental probability is sometimes referred to as relative frequency or empirical probability and it is a ratio of the number of outcomes for the occurrence of a specific event to the total number of trials in an actual experiment.
Next, we would determine the total number of notebooks by adding the frequencies together as follows;
Total number of notebooks = 51 + 38 + 22 + 17 + 66 + 48 + 55 + 23 + 25 + 19 + 25 + 11
Total number of notebooks = 400 notebooks.
In this context, the experimental probability is the quotient of the number of favorable outcome for red notebooks with 150 pages and the total number of notebooks:
P(R) = 66/400
P(R) = 33/200