Question

Use the first and last data points to find the slope intercept equation of a trend line.

Answer 1

y =
`(16)/(3)x-79`

Explanation:

From the given table,

Two points are (1, 15) and (7, 47)

If the two points
`(x_1,y_1)` and
`(x_2,y_2)` are lying on a line then slope 'm' of the line will be,

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

=
`(47-15)/(7-1)`

=
`(32)/(6)`

=
`(16)/(3)`

Let the equation of a line passing through (h, k) is,

y - h = m(x - k)

If the line passes through (1, 15)

y - 1 =
`(16)/(3)(x-15)`

y =
`(16)/(3)x-(16)/(3)(15)+1`

y =
`(16)/(3)x-80+1`

y =
`(16)/(3)x-79`