What's the greatest ten you can multiply by 8 to get close to, but not go over 629

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?

Determine whether the set of whole numbers is closed under addition. explain why the set is or is not closed. give an example.

Consider that lines b and c are parallel. what is the value of x? what is the measure of the smaller angle?