Question

2. A researcher studied 52 giant pandas at three different nature reserves (called “A”, “B”, and “C”). She recorded their daily bamboo intake (in kg), sex, and height (in cm). After confirming all relevant assumptions and mean-centering the “height” variable, she ran a general linear model predicting bamboo intake with the following results:

	Estimate	Standard Error
Intercept	7.101	2.189
Height (centered)	0.242	0.052
Sex_male	2.363	0.419
Reserve_B	-1.872	0.731
Reserve_C	0.677	1.254
Height*Sex_male	-0.023	0.011

Adjusted R² = .271 Model df = 45

1. Calculate the t-statistics for the main effects and interaction terms in the model. Which effects are significant predictors of bamboo intake in this population of pandas? (3pt)
2. Interpret the estimate of Height (centered) in context. (1pt)

3. Interpret the estimate of Height*Sex_male in context. (1pt)

4. Are there significant differences in mean bamboo intake across the three different nature reserves, while accounting for sex and height? Summarize what you know given the above results, citing the appropriate statistics. (2pt)

Answer 1

a. Test for significants of coefficients: EstimateSE stat p-value 7.101 2.189 -3.24395 0.001113 0.242 0.052 4.6538461.44E-05 2.363 0.419 5.6396185.33E-07 1.972 0.731 -2.69767 0.004897 0.6771.254 0.5398720.295973 Intercept Height Sex male Reserve B Reserve_C Height*Sex_male-0.023 0.011 -2.09091 0.021107

Based on p-values, we conclude that "Reserve_C" variable is only insignificant (it:s p-value 0.05), rest all variables are significant. b. For 1 cm increase in height of pandas, there is expcted increase of 0.24 bamboos intake; also, For 10 cm increase in height of pandas, there is expcted increase of 2.4 bamboos intake c. For a male panda 1 com increase in height increases bamboo intake by 2.337 (2.36-0.023) units. d. There is significant differnce between reserve A & B not C since p-value for Reserve_C>.05 e. predicted bamboo is 7.1+80*.242+2.363 1-1.972*1+0-.023 80 10.81
thank you