Step 1 :Define the data with midterm grades as [74, 66, 84, 93, 89, 87, 70, 93, 74, 77] and final grades as [78, 78, 74, 94, 72, 90, 62, 94, 82, 74].
Step 2 :Calculate the means of midterm grades and final grades, which are 80.7 and 79.8 respectively.
Step 3 :Calculate the terms needed for the numerator and denominator of \(b_{1}\). The numerator terms are [12.06, 26.46, -19.14, 174.66, -64.74, 64.26, 190.46, 174.66, -14.74, 21.46] and the denominator terms are [44.89, 216.09, 10.89, 151.29, 68.89, 39.69, 114.49, 151.29, 44.89, 13.69].
Step 4 :Calculate \(b_{1}\) and \(b_{0}\) using the formula \(b_{1} = \frac{\sum \text{{numerator terms}}}{\sum \text{{denominator terms}}}\) and \(b_{0} = \text{{mean of final grades}} - b_{1} \times \text{{mean of midterm grades}}\). The calculated \(b_{1}\) is 0.660 and \(b_{0}\) is 26.503.
Step 5 :\(\boxed{\text{{The equation of the regression line is }} \hat{y}=26.503+0.660x}\)