Question

To evaluate a standard test of the flammability of fabric for children's sleepwear, the American Society for Testing Materials had five laboratories each test 11 pieces of the same type of fabric. The response variable is the length of the char mark made when the fabric sample is held over a flame for a specified time period. Ideally, all labs using the standardized test to test the same fabric should observe about the same value for this response variable. Output for a one-way analysis of variance of the data is shown in the table.

Analysis of Variance for Charling
Source	DF	SS	MS	F
Lab	4	10.269	2.567	15.579
Error	50	8.239	0.165
Total	54	18.508

Assuming that the equal standard deviations assumption is valid, calculate 90% confidence intervals for each of μ₁, μ₂, μ₃, μ₄, and μ₅. (Round all answers to the nearest thousandth.) The output shows the sample means and the pooled standard deviation.

level	N	Mean	StDev
1	11	3.4280	0.4520
2	11	3.5600	0.4592
3	11	3.3000	0.3716
4	11	3.0560	0.2908
5	11	4.3330	0.4314
Pooled StDev = 0.4059

for μ₁ the interval is (  ,  )

for μ₂ the interval is (  ,  )

for μ₃ the interval is (  ,  )

for μ₄ the interval is (  ,  )

for μ₅ the interval is (  ,  )

Answer 1

1) for μ₁ the interval is

2) for μ₂ the interval is

3)for μ₃ the interval is

4) for μ₄ the interval is

5) for μ₅ the interval is