Suppose we are interested in the regression relationship between the variables of X and Y, such as

X 4, 5, 5, 6, 7, 9, 10, 8, 7, 10 and

Y 12, 9, 8, 9, 10, 6, 8, 8, 7, 7

The mean of x_i is 7.1. If we assume the Gauss Markov theorem holds and the regression relationship is given by y_i = b_1 + b_2 * x_i + e_i. Please calculate the mean of the dependent variable.