The following data represents the marks in Algebra (x) and Geometry (y) of a group of 10 students. Find both the regression equations and hence estimate y if x = 78 and x if y = 94.
x =75 80 93 65 87 71 98 68 89 77
y =82 78 86 72 91 80 95 72 89 74
x =75 80 93 65 87 71 98 68 89 77
y =82 78 86 72 91 80 95 72 89 74