12.67 Plant Science An experiment was conducted to determine the effect of soil applications of various levels of phosphorus on the inor- ganic phosphorus levels in a particular plant. The data in the table represent the levels of inorganic phosphorus in micromoles (mol) per gram dry weight of sudan grass roots grown in the greenhouse for 28 days, in the absence of zinc. Use the MINITAB output to answer the questions.

a. Plot the data. Do the data appear to exhibit a linear relationship?

b. Find the least-squares line relating the plant phosphorus levels y to the amount of phosphorus applied to the soil x. Graph the least-squares line as a check on your answer.

c. Do the data provide sufficient evidence to indicate that the amount of phosphorus present in the plant is linearly related to the amount of phosphorus applied to the soil?

d. Estimate the mean amount of phosphorus in the plant if 0.20 mol of phosphorus is applied to the soil, in the absence of zinc. Use a 90% confidence interval.

Transcribed Image Text:

Phosphorus Applied, x 0.5 mol Phosphorus in Plant, y 204 195 247 245 0.25 mol 159 127 95 144 0.10 mol 128 192 84 71