1. **State the problem:** We want to find the least squares regression line fitting the data with $x$ as the independent variable and $y$ as the dependent variable.
2. **Formula for least squares line:** The regression line is given by
$$y = b_0 + b_1 x$$
where
$$b_1 = \frac{n\sum xy - \sum x \sum y}{n\sum x^2 - (\sum x)^2}$$
and
$$b_0 = \frac{\sum y - b_1 \sum x}{n}$$
3. **Given sums from the table:**
$$\sum x = 798$$
$$\sum y = 819$$
$$\sum xy = 66045$$
$$\sum x^2 = 64722$$
$$n = 10$$
4. **Calculate slope $b_1$:**
$$b_1 = \frac{10 \times 66045 - 798 \times 819}{10 \times 64722 - 798^2}$$
Calculate numerator:
$$10 \times 66045 = 660450$$
$$798 \times 819 = 653862$$
$$\text{Numerator} = 660450 - 653862 = 6588$$
Calculate denominator:
$$10 \times 64722 = 647220$$
$$798^2 = 636804$$
$$\text{Denominator} = 647220 - 636804 = 10416$$
So,
$$b_1 = \frac{6588}{10416}$$
Show cancellation:
$$b_1 = \frac{\cancel{6588}}{\cancel{10416}} = \frac{549}{868} \approx 0.632$$
5. **Calculate intercept $b_0$:**
$$b_0 = \frac{819 - 0.632 \times 798}{10}$$
Calculate product:
$$0.632 \times 798 \approx 504.336$$
Subtract:
$$819 - 504.336 = 314.664$$
Divide:
$$b_0 = \frac{314.664}{10} = 31.4664$$
6. **Final regression line:**
$$y = 31.4664 + 0.632 x$$
This line minimizes the sum of squared vertical distances (least squares) between the observed $y$ values and the predicted values from the line.
Least Squares Line 4590D6
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