match each expression with its value if x = -3.

1.
21

2.
9

3.
-12

4.
-18

a.
6x

b.
4x

c.
-3x

d.
-7x

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?

Neoli is a nurse who works each day from 8: 00 am to 4: 00 pm at the blood collection centre. she takes 45 minutes for her lunch break. on average, it takes neoli 15 minutes to collect each sample and record the patient's details. on average, how many patients can neoli see each day?

What is the interquartile range of this data set? 2, 5, 9, 11, 18, 30, 42, 48, 55, 73, 81