The article "Crop Improvement for Tropical and Subtropical Australia: Designing Plants for Difficult Climates" (Field Crops Research, 1991) gave the accompanying data on x = crop duration in days for soybeans and y = crop yield in tons/hectare.
X------ 92 92 96 100 102 102 106 106 121 143
Y------ 1.7 2.3 1.9 2.0 1.5 1.7 1.6 1.8 1.0 0.3
(a) Draw a scatterplot of the raw data and a residual plot. Give interpretations of both.
(b) Conduct a hypothesis test for β. Give the p-value and statement about whether the linear relationship is statistically significant.
(c) Identify any outliers and describe the effect they may have on the analysis.
(d) Give an explanation of the coefficient of determination.
(e) Give a 95% prediction interval estimate for the crop yield corresponding to a crop duration of 105 days.