11. Swampy Sites A study to compare the rates of growth of vegetation at four swampy undeveloped sites involved measuring the leaf lengths of a particular plant species on a preselected date. Six plants were randomly selected at each of the four sites and the mean leaf length per plant (in centimeters) for a random sample of 10 leaves per plant was recorded. The data and a partial MINITAB analysis of variance printout is shown here.

a. Can you be fairly confident that the observations have been selected from normally distributed (at least, roughly so) populations? Explain your answer.

b. Do the data provide sufficient evidence to indicate a difference in mean leaf length among the four locations?
What is the p-value for the test?

c. Suppose, prior to seeing the data, you decided to compare the mean leaf lengths of locations 1 and 4. Test the null hypothesis 1 4 m 5m against the alternative m m 1? 4.

d. Refer to part

c. Construct a 99% confidence interval for ( ) 1 4 m 2m .

Transcribed Image Text:

Location Mean Leaf Length (cm) 1234 5.7 6.3 6.1 6.0 5.8 6.2 2 6.2 5.3 5.7 6.0 5.2 5.5 5.4 5.0 6.0 5.6 4.9 5.2 4 3.7 3.2 3.9 4.0 3.5 3.6