Answer:
20% tip is $3.97, add that to 18.97 and you get $22.76, then add 8.25 and you get $31.01
Step-by-step explanation:
Regression analysis is used to infer about the relationship between two or more variables.
The line of best fit is a straight line representing the regression equation on a scatter plot. The may pass through either some point or all points or none of the points.
<u>Method 1:</u>
Using regression analysis the line of best fit is: 
Here <em>α </em>= intercept, <em>β</em> = slope and <em>e</em> = error.
The formula to compute the intercept is:

Here<em> </em>
and
are mean of the <em>y</em> and <em>x</em> values respectively.

The formula to compute the slope is:

And the formula to compute the error is:

<u>Method 2:</u>
The regression line can be determined using the descriptive statistics mean, standard deviation and correlation.
The equation of the line of best fit is:

Here <em>r</em> = correlation coefficient = 
and
are standard deviation of <em>x</em> and <em>y</em> respectively.

Answer:
48 meters
Step-by-step explanation:
The first thing is to calculate the scale, since we know both widths it is possible:
we pass the 9 meters to centimeters = 900 cm
900/6 = 150
So the scale would be 1: 150
Which means that the length is 150 times bigger.
10 * 150 = 1500cm or what equals 15m
the perimeter is the sum of all the sides, therefore:
P = 15 + 15 + 9 + 9
P = 48
Which means that the perimeter of the room is 48 meters
Answer:

Step-by-step explanation:
The given equation is 
Group similar terms to get:


Square both sides to obtain:


Add 6 to both sides

Simplify the right hand side to obtain;
