1 คือโจทย์ให้ sample size ,sample total , sum of squre observation คือ ค่าเฉลี่ยเอา sample total / sample size ได้เรยไหมคะ แล้วค่า sum of squre observation คืออะไรอะคะ   แล้วจะหา ssw ,ssb ยังไง
2) Drug for prevention of BP increase
There will be an increase in systolic blood pressure during endotracheal intubation.
This increase can have deleterious effects on the cardiovascular system. Two drugs, Drug A
and Drug B, are used to prevent this increase in BP. An investigator wanted to test the
beneficial effects of these drugs. Patients undergoing endotracheal intubations were
randomly divided into three groups, namely, control group, Drug A group, Drug B group.
BP was recorded at 5 min of endotracheal intubation. The increase in blood pressure (the
difference between BP prior to endotracheal intubation and at 5 min of endotracheal
intubation) was tabulated.
Increase in BP with Drugs A and Drug B
  
group               increase in BP
control n=98     40บวกลบ 12
drug a  n=122    29บวกลบ11
drug b  n=101    25บวกลบ14
อันนี้คืองงมากๆ จะหา ssw ssb ยังไงอ่ะคะ