A health educator wants to evaluate the effect of a dental film on the frequency with which children brush their teeth. A random selection of 8 children is used for the experiment.First, a baseline of the number of times the children brush their teeth over a month's period is established.Next, the children are shown the dental film and again the number of teeth brushings are recorded for a month.The following data are recorded:

Subject

1

2

3

4

5

6

7

8

After Film

28

29

25

30

25

27

28

24

Baseline

25

28

22

30

26

24

25

22

What is the nondirectional alternative hypothesis?

df =

D2=

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Dobt=

D=

SSD=

(D)2=