The librarian was checking the thicknesses of several books and found that the average thickness of a book was 1.8 centimeters. She found this by averaging the thicknesses of five different books. Four of the thicknesses were 1.4 cm, 1.9 cm,
2.1 cm, and 2.4 cm. What was the thickness of the fifth book that she measured?

Need now max recorded the heights of 500 male humans. he found that the heights were normally distributed around a mean of 177 centimeters. which statements about max’s data must be true? a) the median of max’s data is 250 b) more than half of the data points max recorded were 177 centimeters. c) a data point chosen at random is as likely to be above the mean as it is to be below the mean. d) every height within three standard deviations of the mean is equally likely to be chosen if a data point is selected at random.

Which type of graph would allow us to quickly see how many students between 100 and 200 students were treated?

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.