Question

Draw a line of fit using 20, 25 and 25,30

Answer 1

The equation is

`y=1.08989x+3.3427`

To find this equation we need to find the sum of all the values of x and y:

`\begin{gathered} S_x=240 \\ S_y=295 \end{gathered}`

the mean for each variable is:

`\begin{gathered} M_x=24 \\ M_y=29.5 \end{gathered}`

The sum of squares for each variable is:

`\begin{gathered} SS_x=890 \\ SS_y=970 \end{gathered}`

now the regression equation is given as:

`y=mx+b`

where m is:

`m=(SS_x)/(SS_y)`

and

`b=M_y-mM_x`

then:

`\begin{gathered} m=(970)/(890)=1.08989 \\ b=29.5-1.08989\cdot24=3.3427 \end{gathered}`