Contaminated fish in the Tennessee River. Refer to the U.S. Army Corps of Engineers data on contaminated fish, saved in the DDT file. The results of an ANOVA and Tukey multiple-comparison analysis to compare the three fish species (channel catfish, largemouth bass, and smallmouth buffalo) on the dependent variable length (in centimeters)

are shown in the following MINITAB printout.

a. Is there sufficient evidence (at a = .01) to conclude that the mean lengths differ among the three fish species?

b. What is the experimentwise error rate for the Tukey multiple comparisons?

c. Locate the confidence interval for the difference 1mbass - mcatfish2. Are the two means significantly different?
If so, which mean is significantly larger?

d. Locate the confidence interval for the difference 1mbuffalo - mcatfish2. Are the two means significantly different? If so, which mean is significantly larger?

e. Locate the confidence interval for the difference 1mbuffalo - mbass2. Are the two means significantly different?
If so, which mean is significantly larger?

Transcribed Image Text:

One-way ANOVA: LENGTH versus SPECIES Source SPECIES DF SS MS F 2 3533.1 1766.5 76.88 P 0.000 Error 141 3239.9 23.0 Total 143 6772.9 S = 4.794 R-Sq 52.16% R-Sq (adj) - 51.49% Level N Mean StDev CHANNELCATFISH 96 44.729 4.581 LARGEMOUTHBASS 12 26.542 4.480 SMALLHOUTHBUFF 36 43.125 5.413 Pooled StDev = 4.794 Tukey 95% Simultaneous Confidence Intervals All Pairwise Comparisons among Levels of SPECIES Individual confidence level 98.08% SPECIES CHANNELCATFISH subtracted from: SPECIES Lover Center Upper LARGEMOUTHBASS -21.664 -18.188 -14.711 SMALLMOUTHBUFF -3.823 -1.604 0.615 SPECIES LARGEMOUTHBASS subtracted from: SPECIES Lover Center Upper SMALLHOUTHBUFF 12.798 16.583 20.368