(See Steps) A linear model of the form y_i=β_1 x_i+β_0 for i=1,2,... , n observations (x_i, y_i), has the linear least squares solution for the


Question: A linear model of the form

\[\mathrm{y}_{\mathrm{i}}=\beta_{1} \mathrm{x}_{\mathrm{i}}+\beta_{0}\]

for \(i=1,2,\ldots \), n observations \(\left(\mathrm{x}_{\mathrm{i}}, \mathrm{y}_{\mathrm{i}}\right)\), has the linear least squares solution for the parameters \(\beta_{1}\) and \(\beta_{0}\) of

\[\hat{\beta}_{1}=\frac{\sum_{i=1}^{n}\left(y_{i}-\bar{y}\right)\left(x_{i}-\bar{x}\right)}{\sum_{i=1}^{n}\left(x_{i}-\bar{x}\right)^{2}}\]

and

\[\begin{aligned} & {{{\hat{\beta }}}_{0}}=\bar{y}-{{{\hat{\beta }}}_{1}}\overline{\text{x}} \\ & \overline{\text{x}}=\sum\limits_{\text{i}=1}^{\text{n}}{\frac{{{\text{x}}_{\text{i}}}}{\text{n}}}\text{ and }\overline{\text{y}}=\sum\limits_{\text{i}=1}^{\text{n}}{\frac{{{\text{y}}_{\text{i}}}}{\text{n}}} \\ \end{aligned}\]

The variance of the error,

\[\sigma^{2}=\operatorname{Var}\left[y_{i}-\left(\beta_{1} x_{i}+\beta_{0}\right)\right]\]

may also be estimated by

\[\sigma^{2}=\frac{1}{n-2} \sum_{i=1}^{n}\left(y_{i}-\hat{\beta}_{0}-\hat{\beta}_{1} x_{i}\right)^{2}\]

For the following two sets of data \(y_{i}\) and \(z_{i}\)

\[{{X}_{i}}\] \[{{Y}_{i}}\] \[{{Z}_{i}}\]
1 6.7 3.9
2 4.7 1.5
3 8.1 -0.2
4 7.1 1
5 11.3 0.6
6 10.5 -3.1
7 11.8 -2.8
8 13.7 -1.8
9 10.6 -6
10 13.3 -5
  1. Compute the regression coefficients \(\beta_{0}\) and \(\beta_{1}\) and \(\sigma^{2}\) for the two sets of data \(\left(\mathrm{x}_{\mathrm{i}}, \mathrm{y}_{\mathrm{i}}\right)\) and \(\left(\mathrm{x}_{\mathrm{i}}, \mathrm{z}_{\mathrm{i}}\right)\)
  2. Plot the raw data and the lines determined in a for both sets of data.
  3. Compute the correlation coefficient \(r_{x y}\) for the both sets of data.
  4. How do you interpret these correlation coefficients?

Price: $2.99
Solution: The downloadable solution consists of 5 pages
Deliverable: Word Document

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