Answer
The linear model is not appropriate.
Work Step by Step
There is nonconstant error variance in the given residual plot.
The magnitude of the residuals decreases substantially as the explanatory variable increases.
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.