A manufacturer of cases for sound equipment requires that holes be drilled for metal screws. The drill bits wear out and must be replaced; there is expense not only in the cost ofthe bits but also in the cost of lost production. Engineers varied the rotation speed of the drill and measure the lifetime of four bits at each of five speeds. In this regession model, which is the dependent variable? speed at which holes were drilled lifetime of drill bits lifetime of drill bits and speed at which holes were drilled None of the listed answers is correct Which of the following is true about the least squares estimates of the slope and intercept? A They minimize Bo and B1 B They minimize Z = (x, - x,)2 C They minimize Z,=1(), -DD) D They minimize Z,=1(v, -D,)2 E They minimize Z, = (v, - V)2