Question

costumers:54| 46| 34| 67| 52| 22| 49| 64| 55| 80| 38| 42|tips:$92| $80| $76| $121| $109| $43 |$87 | $114|$99| $174| $88| $91|.Find the equation of the trend line

Answer 1

To fidn the euatio of the trend line:

1. Identify two points (x,y) in the line:

(30, 25) and (120,60)

2. Find the slope m:

Formula to find the slope:

`m=(y_2-y_1)/(x_2-x_1)`

For the trend line:

`m=(60-25)/(120-30)=(35)/(90)=(7)/(18)`

3. Find the y-intercept b:

Use the value of the slope and one point in the from y=mx+b:

(30,25) x= 30, y=25

m=7/18

`\begin{gathered} 25=(7)/(18)(30)+b \\ \\ 25=(210)/(18)+b \\ \\ 25-(210)/(18)=b \\ \\ (450-210)/(18)=b \\ \\ (240)/(18)=b \\ \\ (40)/(3)=b \end{gathered}`

4. Write the equation with the values of m and b you find:

`\begin{gathered} y=(7)/(18)x+(40)/(3) \\ \\ \end{gathered}`