Question

Is the data point, P, an outlier, an influential point, both, or neither?

The regression equation for a set of paired data is = –23.8 + 2x. The values of x run from 100 to 400. A new data point, P(194, 364.2), is added to the set.


a. Influential point

b. Outlier

c. Both

d. Neither

Answer 1

Option a) Influential point is correct.

∴ the point P(194,364.2) is an influential point.

Explanation:

Given that the regression equation for a set of paired data is = -23.8 + 2x. The values of x run from 100 to 400.

A new data point, P(194, 364.2), is added to the set.

From the given we can write it as y = -23.8+2x

Put x=194 in the above equation we get,

`y(194) = -23.8+2* 194`

`=-23.8+ 388`

= 364.2

∴ y(194)=364.2

Hence, point P(194,364.2) is on regression line and it is not outlier.

∴ the point P(194,364.2) is an influential point.

Hence option a) Influential point is correct.