Need Help! 50 Points! A set of quiz scores is shown in the histogram below. The mean of the data set is 6.625, and the (population) standard deviation is 1.9.

How many numbers in the data set are within 1 standard deviation of the mean?

7
13
10
12

Ineed to learn how to solve this problem

What is the frequency of the sinusoidal graph?

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?