HW11-SS22: Problem 8

Problem Value: 9 point(s). Problem Score: 0%. Attempts Remaining: 3 attempts.

(9 points)

Electric fruit ~ Plant physiologists study the fruit ripening process to understand how best to grow and store fruit that is satisfying to eat. Past research has shown that when stonefruit such as peaches and nectarines are stored at low temperatures for extended periods, the texture of the fruit becomes dry or mealy.Plant biology researchers studying the changes in the cells of fruit as it matures took a random sample of 44 nectarines that had been stored at cold temperatures for a few weeks. They measured the apparent juice content (juice) and the electrical resistance in kiloohms (resistance) of the fruit.The scatter plot and a summary of the data is given below. The correlation between juice and resistance was found to be r = -0.7503.Round all calculated answers to 4 decimal places.

Variables	Mean	Sample SD
Resistance	5.597	1.968
Juice	21.1477	10.1921

1. The relationship between resistance and juice is best described as ??? Positive Negative and ??? Linear Nonlinear .2. Calculate the slope and intercept for the linear regression equation that predicts juice from resistance.Note: Do not use rounded values for intermediate calculations!Slope: and Intercept: 3. Fill in the blanks: The coefficient of determination, R2R2, for the linear regression model of juice from resistance is . This means that % of the variation in ??? juice resistance nectarines can be explained by its linear relationship to ??? juice resistance nectarines .4. As part of the analysis, the researchers examined the residuals for the regression model to determine if the conditions for linear regression have been met. Which condition did the researchers check with the following plot?

A. The researchers were checking to see if the residuals are within the range of data used to construct the model. B. The researchers were checking the strength of the evidence that the slope of the regression line is nonzero. C. The researchers were checking to see if the residuals are nearly normal. D. The researchers were checking to see if the variability of points around the least squares line was roughly constant.