Applicants for a Particular Job, Which Involves Extensive Travel in Spanish

Essay

Applicants for a particular job, which involves extensive travel in Spanish speaking countries must take a proficiency test in Spanish. The sample data below were obtained in a study of the relationship between the numbers of years applicants have studied Spanish (x) and their score on the test (y) .
$\begin{array} { l r r r r r r r r r r } \hline x & 3 & 4 & 4 & 2 & 5 & 3 & 4 & 5 & 3 & 2 \\\hline y & 57 & 78 & 72 & 58 & 89 & 63 & 73 & 84 & 75 & 48 \\\hline\end{array}$
The regression equation $\hat { y } = 31.55 + 10.90 x$ was obtained. Construct a residual plot for the data.