Uhhh help? I’ve never really used this app but I need help

The head librarian at the library of congress has asked her assistant for an interval estimate of the mean number of books checked out each day. the assistant provides the following interval estimate: from 740 to 920 books per day. what is an efficient, unbiased point estimate of the number of books checked out each day at the library of congress?

Sketch one cycle if the cosine function y=2cos2theta

Which of the following would be a good name for the function that takes the weight of a box and returns the energy needed to lift it?