Microsoft Office Tutorials and References

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Suppose that your research yields the following conﬁdence interval:

----------------30----------------- 31--------------32--------------- 34---------------

lower

limit

Mean

upper

limit

Ref.

Value

Result:

Since the reference value is outside the conﬁdence interval, we reject the

null hypothesis and accept the research hypothesis.

The three rules for stating the conclusion would be:

Rule #1: We must include the word “signiﬁcantly” since the reference value of

34 is outside the conﬁdence interval.

Rule #2:

The key terms would be:

– Honda Accord Sedan

– signiﬁcantly

– either “more than” or “less than”

– and probably closer to

Rule #3:

The Honda Accord Sedan got signiﬁcantly less than 34 mpg, and it was

probably closer to 31 mpg.

Note that this conclusion says that the mpg was less than 34 mpg because the

sample mean was only 31 mpg. Note, also, that when you ﬁnd a signiﬁcant result by

rejecting the null hypothesis,
it is not sufﬁcient to say only: “signiﬁcantly less than

34 mpg
,
”
because that does not tell the reader “how much less than 34 mpg” the

sample mean was from 34 mpg. To make the conclusion clear, you need to add:

“probably closer to 31 mpg” since the sample mean was only 31 mpg.

CASE #2:

The National Association of Biology Teachers (NABT) is an

American-based scholarly Life Sciences society with more than

5,000 members. The NABT hosts an annual Professional

Development Conference for four days that focuses on the teaching of biology

and the life sciences in the 21
st
century. The conference includes

hands-on workshops and informative sessions for participants.

Suppose that the NABT wanted to use an Internet Survey to evaluate the

annual conference based on responses from the participants. Let’s

suppose that you have been asked to perform the data analyses for

the returned surveys, and that you want to practice your data analysis

skills on the hypothetical Item #15 given in Fig.
3.8
:

The hypotheses for this one item would be:

m
═

H
0
:

4

H
1
:

m
6¼

4

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