Some soap manufacturers sell special antibacterial soaps How

Some soap manufacturers sell special anti-bacterial soaps. However, one might expect that ordinary soap kills bacteria as well. To investigate this, a researcher prepared a solution of ordinary (non-antibacterial) soap and a solution of sterile water (control). The two solutions were placed in petri dishes and E. coli bacteria were added. The dishes were then incubated and the number of colonies of bacteria in each dish was counted. The data are given in the following table. Fill in the missing boxes and obtain a 95% confidence interval for the difference between the true means of groups I and II.

Control I

Soap Solution II

30

76

36

27

66

16

21

30

63

26

38

46

35

6

45

# samples n

8

7

Sample mean

Sample standard dev

SE(Mean)

SE(Diff Mean)

Solution