Biologists have found that there is a relationship between the rate of a cricket's chirp and the temperature. A regression model is determined, with the predictor variable x=x= chirps per second and the response variable y=y= temperature (F). The data on which the model is based is given below, along with output of the regression analyis.

Chirps	13	14	15	15	16	17	18	20	20	23
Temperature	64.8	74	74	76	72	72.5	74.8	84	90	87.5

Correlation Coefficient:	r= 0.87
Least Squares Equation:	y=40.1+2.16x

a. Use the given regression line equation to predict the temperature (round to 1 decimal place) if the rate of cricket chirps is:

• 19 chirp/sec, predicted temp== F
• 27 chirp/sec, predicted temp== F

b. Is one of these predictions more reliable than the other?

• The prediction corresponding to 27 chirps/sec is more reliable.
• The prediction corresponding to 19 chirps/sec is more reliable.
• Both predictions are equally reliable since they are based on the same regression model.

c. Use the following box to explain why the answer you chose in part b) is correct. Please note: this part of the question is not automatically graded. Your Professor will read your response after the due date to grade it manually. Please be patient for this part!

d. The coefficient of determination is the square of the correlation. That is, the coefficient of determiniation is r2.r2. When changed from a decimal to a percent, r2r2 tells us what percent of the variation in one variable can be explained by variation in the other. Based on the linear regression model, what percentage of the variation in xxcan be explained by the corresponding variation in yy?

• 93.3 %
• 40.1 %
• 2.16 %
• 87 %
• 75.7 %