Consider the data with analysis shown in the following computer output: Level N Mean StDe'ur A 5 37.331 5.603 B 5 76.167 6.555 C 7 30.000 9.230 D 7 69.333 6.154 SourCe DF 55 MS F P Groups 3 1010.81 336.94 6.51 0.003 E rro r 20 1035. B3 5 1. .79 Total 23 2046.64 What is the pooled standard deviation? What degrees of freedom are used in doing inferences for these means and differences in means? Round your answer for the pooled standard deviation to two decimal places. The pooled standard deviation is a