Final answer:
To find the probability of randomly selecting a cookie from the bag, divide the number of cookies of a specific type by the total number of cookies in the bag. Then, add up the probabilities of selecting each type of cookie to find the probability of randomly selecting any type of cookie from the bag.
Step-by-step explanation:
To find the probability of randomly selecting a cookie from the bag, we need to determine the total number of cookies in the bag. The bag contains 4 chocolate chip cookies, 7 peanut butter cookies, 5 sugar cookies, and 5 oatmeal cookies. So, the total number of cookies in the bag is 4 + 7 + 5 + 5 = 21.
To find the probability of randomly selecting a cookie, we need to divide the number of cookies of a specific type by the total number of cookies in the bag. For example, the probability of randomly selecting a chocolate chip cookie would be 4/21. Similarly, you can find the probability of randomly selecting a peanut butter cookie, a sugar cookie, or an oatmeal cookie by dividing the respective number of cookies by 21.
The probability of randomly selecting any type of cookie from the bag can be found by adding up the probabilities of selecting each type of cookie. For example, the probability of randomly selecting a chocolate chip or a peanut butter cookie would be (4/21) + (7/21) = 11/21.