Answer:
1) y = 1.8741176487x + 3.655964863
2) About $191 using the equation, about $180 or more using the data you are given.
3) I can use the regression calculator by using the largest number of customers you have in the data set and lowest number of customers and compare them to see if the numbers are in ascending or descending order.
Answer:

13 glue sticks cost $25.22.
Step-by-step explanation:
4 blue sticks cost $7.76, this means that one glue stick costs
$7.76/4 = $1.94.
Let
be the cost of the glue sticks, and
be the number of glue sticks; then

We can use this equation to find the cost of 13 glue sticks; we just put
into our equation and it gives:

So 13 glue sticks cost $25.22.