Zero, if she sold 5 scarves & it doesn’t say anything about hats
Answer: Period = 4
Amplitude = 3
<u>Step-by-step explanation:</u>
Period is the interval of one "cycle" before the pattern repeats.
If you notice that when x = 0, y = -4.
When does the pattern repeat (reach -4 again)?
Answer: when x = 4.
So the interval of one "cycle" is 4 units --> Period = 4.

Answer:

Step-by-step explanation:
Let's solve this problem step-by-step. The library had 1,500 books in 2011. The ratio of books in 2011 and in 2012 is 1:2. Therefore, let the number of books in 2012 be
.
We have the following proportion:

Therefore, there were 3,000 books in 2012. The ratio of books in 2012 and in 2013 is 2:5. Let the number of books in 2013 be
.
We have:

Therefore, there were 7,500 books in 2013.
The difference between the smoker and the non-smoker is $151
1000 x $7.85 = $785
1000 x $9.36 = $936
= $151