a. Present this data as a fully labelled scattergram. The chart should include an informative caption. The
Question:
- a. Present this data as a fully labelled scattergram. The chart should include an informative caption. The chart should be created using Excel or a similar tool, and should include a trend line.
b. Inspection of the timber produced from the harvest reveals that one of the trees harvested was NOT a blackbutt tree, but another species with very different yield characteristics. From your scattergram in part (a) identify which point is most likely to correspond to this different tree. Explain what impact the inclusion of data for this tree would have had on the trendline that you included in your diagram.
c. Remove the point that you identified in part (b) from your data set. Using the remaining 29 data points, find the ordinary least squares (OLS) line of best fit that uses CBH to explain or predict tree yield. Provide an interpretation of the slope.
d. Determine and interpret the coefficient of determination.
e. Determine and interpret the standard error of the estimate. Explain how you could graphically sanity check your value for the standard error of the estimate.
f. Use your regression equation to predict the yield of a blackbutt tree with a CBH of 380 centimeters. Explain why this prediction might be problematic.
g. Briefly describe each of the LINE assumptions associated with performing a hypothesis test on the existence of a linear relationship. Test using a=5% whether the apparent linear relationship between CBH and Yield can be explained by chance and be careful to clearly state both your decision and your conclusion.