Exercise 5.46 presented data on x = squawfish length and y = maximum size of salmonid consumed, both in mm. Use the accompanying MINITAB output along with the values x̅ = 343.27 and S_xx = 69,112.18 to answer the following questions.

a. Does there appear to be a useful linear relationship between length and size?

b. Does it appear that the average change in maximum size associated with a 1-mm increase in length is less than .8 mm? State and test the appropriate hypotheses. 

c. Estimate average maximum size when length is 325 mm in a way that conveys information about the precision of estimation.

d. How would the estimate when length is 250 mm compare to the estimate of Part (c)? Answer without actually calculating the new estimate.

Data from Exercise 5.46

The paper “Feeding of Predaceous Fishes on Out-Migrating Juvenile Salmonids in John Day Reservoir, Columbia River” (Transactions of the American Fisheries Society [1991]: 405–420) gave the following data on y = maximum size of salmonids consumed by a northern squawfish (the most abundant salmonid predator) and x = squawfish length, both in millimeters:

Use the accompanying output from MINITAB to answer the following questions.

Transcribed Image Text:

The regression equation is Size = -89.10.729length Predictor Constant Coef 89.09 length 0.72907 s = 12.56 R-sq = 96.3% Source DF Regression Error Total 1 9 10 Stdev 16.83 t-ratio 5.29 15.26 p 0.000 0.04778 0.000 R-sq(adj) = 95.9% Analysis of Variance SS F 36736 232.87 1420 38156 MS 36736 158 p 0.000