An urgent detailed response is needed as soon as possible
And explain how to interpret numerical values in degrees(°) to their corresponding given data

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?

Im literally having a mental breakdown

Prove that the value of the expression 7^8–7^7+7^6 is divisible by 43.