the probability is 0.6 that a person shopping at a certian store will spend less than $20. For group of size 19, find the mean number who spend less then $20.
0.6 x 19 = 11.4
To find the mean number of people who spend less than $20 in a group of size 19, we can use the concept of expected value. The expected value represents the average outcome of an experiment or event.
The probability that a person will spend less than $20 at the store is given as 0.6. Therefore, the probability that a person will spend $20 or more is equal to 1 - 0.6 = 0.4.
Now, we need to determine the expected value for each person in the group. Since there are 19 people in the group, we multiply the probability by the number of people:
Expected value per person = 0.6 * 1 + 0.4 * 0 = 0.6
Finally, to find the mean number of people who spend less than $20 in the group, we multiply the expected value per person by the total number of people:
Mean number of people who spend less than $20 = 0.6 * 19 = 11.4
Therefore, the mean number of people who spend less than $20 in a group of size 19 is approximately 11.4.