A hydrologist believes that there has been a reduction in the mean water volume passing through a dam. He measured ow at ten specic points on the dam last year (Time 1). He has since remeasured ow at the same points at the same time of year (Time 2). Compute the test statistic (using Time 1 Time 2), using Excel or Minitab to calculate Band Sd_ _[m_m \"m \"m- \"m \