Question

A study of nutrition in developing countries collected data from the Egyptian village of Nahya. Researchers recorded the mean weight (in kilograms) for 170 infants in Nahya each month during their first year of life. A hasty user of statistics enters the data into software and computes the least-squares li~thout looking at the scatterplot first. The result is weight= 4.88 + 0.267 (age).
Required:
Use the residual plot to determine if this linear model is appropriate.

Answer 1

Answer:

The linear model is not appropriate.

Step-by-step explanation:

In regression, the difference amid the observed-value of the dependent-variable (y) and the predicted-value ($\hat y$) is known as the residual (e).

$e=y-\hat y$

A residual plot is a graphical representation of the residuals on the y-axis and the independent variable on the x-axis. If the data-points on the residual plot are randomly spread around the x-axis, a linear regression model is appropriate for the data. And if the residual plots shows a non-random or a U or inverted U pattern, a nonlinear model is more appropriate for the data.

The residual provided shown an inverted U pattern. That is the points are not scattered around he graph.

Thus, the linear model is not appropriate.