Consider the data with analysis shown in the following computer output:

Level	N	Mean	StDev
A	6	86.371	5.191
B	5	76.167	6.555
C	6	80.000	9.230
D	7	69.333	6.154

Source	DF	SS	MS	F	P
Groups	3	986.59	328.86	6.85	0.002
Error	20	959.80	47.99
Total	23	1946.39

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_______________________

degree of freedom is ______________