# Question: The focal point of an agricultural research study was the

The focal point of an agricultural research study was the relationship between when a crop is planted and the amount of crop harvested. If a crop is planted too early or too late farmers may fail to obtain optimal yield and hence not make a profit. An ideal date for planting is set by the researchers, and the farmers then record the number of days either before or after the designated date. In the following data set, D is the deviation (in days) from the ideal planting date, and Y is the yield ( in bushels per acre) of a wheat crop:

a. Plot the above data. Does a linear relation appear to exist between yield and deviation from the ideal planting date?

b. Plot yield versus absolute deviation from the ideal planting date. Does a linear relation seem more appropriate in this plot than the plot in part (a)?

a. Plot the above data. Does a linear relation appear to exist between yield and deviation from the ideal planting date?

b. Plot yield versus absolute deviation from the ideal planting date. Does a linear relation seem more appropriate in this plot than the plot in part (a)?

## Answer to relevant Questions

Refer to Exercise 11.24. Fit a regression model relating yield to the absolute deviation from the ideal planting date, that is, x = | D|. a. Compute the estimated linear regression model = β0 + β1x. b. Estimate σ2e. c. ...Use the data given here to answer the following questions. a. Plot the data values in a scatter diagram. b. Sketch a straight line through the points. c. Use your sketched line to predict the value of y when x = 40. Use the data from Exercise 11.22. a. Estimate the mean time to run 10 km for athletes having a treadmill time of 11 minutes. b. Place a 95% confidence interval on the mean time to run 10 km for athletes having a treadmill ...Refer to Exercise 11.27. a. Compute the value of r2yx. b. What are the value and sign of the correlation coefficient? c. Suppose the study in Exercise 11.27 had been restricted to RunSize values less than 1.8. Would you ...Refer to Exercise 11.50. a. Place a 95% confidence interval on the six correlations. b. Using the confidence intervals from part (b), are there any differences in the degree of correlation between male and female math ...Post your question