3.1.32 Question Help Mr. Zuro finds the mean height of all 13 students in his statistics class to be 68.0 inches. Just as Mr Zuro finishes explaining how to get the mean, Danielle walks in late Danielle is 72.2 inches tall. What is the mean height of the 14 students in the class? The mean height of the 14 students in the class is inches​

Ineed with number 17 i don’t get it at alll

Quick! a survey of 57 customers was taken at a bookstore regarding the types of books purchased. the survey found that 33 customers purchased mysteries, 25 purchased science fiction, 18 purchased romance novels, 12 purchased mysteries and science fiction, 9 purchased mysteries and romance novels, 6 purchased science fiction and romance novels, and 2 purchased all three types of books. a) how many of the customers surveyed purchased only mysteries? b) how many purchased mysteries and science fiction, but not romance novels? c) how many purchased mysteries or science fiction? d) how many purchased mysteries or science fiction, but not romance novels? e) how many purchased exactly two types of books?

Precalculus question, image attached.