Answer: 28
Step-by-step explanation:
The mean of 15 numbers = 12
Then , the sum of the numbers = 12x15 = 180
Let the extra number included be
, then
The new sum = 
And the new total number will increase from 15 to 16
new mean = 13 , so we have :





therefore , the extra number is 28
The more fuel efficient car is the car that has 28 miles to a gallen.She would be saving 752 dollars.
Answer:
You will find the answer easily after doing the steps below.
Step-by-step explanation:
If you have graph paper, this is really easy to do. All you need to do is draw a graph. Then you will number the squares. Next, find the points (-2, 7) and (6, -9). Draw a line connecting the two points you have created.