Question

Head width (cm)	Biting force (grams/centimer2)
4.31	129.8
3.92	114.5
2.56	91.8
3.72	109.8
4.21	122.7
2.95	103.5
4.74	134.6
2.84	115.1

Imagine that you are examining the functional relationship between head width (measured in centimeters) and biting force (measured in grams per square centimeters) in the tegu lizard.

a) Conduct a linear regression by hand. You will need to show the slope and the intercept of the best-fit line. Also, construct a scatterplot graph with all data-points and trace the best-fit line (if you want you can do the graph in Excel)

b) Conduct a hypothesis test for the significance of the slope of the best fit line (ANOVA table).

c) Calculate a 95% confidence interval on the slope.

d) Calculate the coefficient of determination (r2).

Show your work and explain all results!

Answer 1

a. 

coefficient of determination =r^2 = (0.8867) ^2 = 0.7862