A clinical psychologist wished to compare three methods for reducing hostility levels in university students using a certain psychological test (HLT). High scores on this test were taken to indicate great hostility, and 11 students who got high and nearly equal scores were used in the experiment. Five were selected at random from among the 11 students and treated by method A, three were taken at random from the remaining six students and treated by method B, and the other three students were treated by method C. All treatments continued throughout a semester, when the HLT test was given again. The results are shown in the table.

Method	Scores on the HLT Test
A	71	82	77	69	79
B	53	75	70
C	78	96	87

Let_Aand_B, respectively, denote the mean scores at the end of the semester for the populations of extremely hostile students who were treated throughout that semester by method A and method B.

(a) Find a 95% confidence interval for _A. (Round your answers to two decimal places.)

to (b) Find a 95% confidence interval for _B. (Round your answers to two decimal

-to (c) Find a 95% confidence interval for (_AB). (Round your answers to two decimal places.) to -

2. A national home builder wants to compare the prices per 2.4 cubic metres board of standard or better grade Douglas fir framing lumber. He randomly selects five suppliers in each of the four provinces where the builder is planning to begin construction. The prices are given in the table.

Province
1 ($)	2 ($)	3 ($)	4 ($)
241	216	232	245
235	220	225	250
238	205	235	238
247	213	228	255
250	220	240	256

(b) Construct the analysis of variance table for this data. (Round your answers to one decimal place.)

Source	df	SS	MS
Treatments
Error
Total

3. Test statistic: F = 4. Rejection region: F >