Final answer:
To evaluate 3b for b = 4 3/4, convert 4 3/4 to an improper fraction 19/4, then multiply 3 by 19/4 to get 57/4, which is in simplest form.
Step-by-step explanation:
To evaluate 3b for b = 4 3/4, first express the mixed number 4 3/4 as an improper fraction. The mixed number 4 3/4 is equal to 19/4 because 4 times 4 equals 16 plus 3 equals 19, which gives 19/4. Now, multiply 3 by 19/4, which equals 57/4. This fraction is already in its simplest form, as 57 and 4 share no common factors other than 1.
Therefore, the result of evaluating 3b when b = 4 3/4 is 57/4.