IPS 5/e	Moore & McCabe		Ex. 7.41
(IPS 4/e formulation)
"The table below gives the pretest and posttest scores on the MLA
listening test in French for 20 high school French teachers
who attended an intensive summer course in French."
Subject	Pretest	Posttest	Gain	Sign
1	32	34
2	31	31
3	29	35
4	10	16
5	30	33
6	33	36
7	22	24
8	25	28
9	32	26
10	20	26
11	30	36
12	20	26
13	24	27
14	24	24
15	31	32
16	30	31
17	15	15
18	32	34
19	23	26
20	23	26
"(a)	We hope to show that attending the institute improves listening skills.
	State an appropriate Ho and Ha.  Be sure to identify the
	parameters appearing in the hypotheses.
"(b)	Make a graphical check for outliers or strong skewness in the data that
	you will use in your statistical test, and report your conclusions on the
	validity of the test."
0.	State your background assumptions.				See IPS p. 463.
"( c)	Carry out a test.  Can you reject Ho at the 5% significance level?
	At the 1% significance level?
"(d)	Give a 90% confidence interval for the mean increase in listening score
	due to attending the summer institute."
(e)	Also carry out a sign test of the same hypotheses.