The South Dakota Department of
The South Dakota Department of Game and Fish (SDDGF) wants tolengthen the pheasant-hunting season to bring in more touristrevenue. SDDGF’s thinking is that most pheasants are killed duringthe first 2 weeks of the season; therefore, a longer season willnot deplete the bird population. Using sample data from all pasthunting seasons, Rodney Ringneck, the SDDGF’s data analyst,regresses the number of birds surviving the season on the length indays in the season.
He finds: Y=547,000-214X; s.e.b =415; R2 = .15; n = 35.
(a) Interpret the intercept and slope, test the slope forsignificance, and interpret the R-squared.
(b) Predict how many birds will survive if the season is 60 dayslong.
(c) Is SDDGF’s thinking correct (that a longer season will notsignificantly deplete the bird population)?
How would I show regression in Excel using the data analysistool?
Answer:
A). Y=547,000-214X
Intercept – that means when x is Zero ( at day 0, beginning)number of birds are 547,000
Slope – If the season is 1 day long then number of birdswould be killed are 214.
test the slope for significance – T value = -214/415 = 0.515663.By checking the P( >|t|) value you can take the decision
R square = Sum of squared Regression / Sum of square Total. Herevalue is 0.15 that means only 15% of total variance can beexplained by the independent variable.
B). Number of birds birds will survive if the seasonis 60 days long = 547,000 – 214 *60 = 547,000 – 12,840 =534,160
C). SDDGF’s thinking is not correct, that means alonger season will significantly deplete the bird populationbecause the slope value is 214 and negative. When X will takelarger value then Y value will decrease based on the equation.
Regression inExcel using the data analysis tool
You have to select “Regression” in data analysis tool. Pleasemention “Input Y range” and “Input X range” in the suitable boxes.In the output option mention “Output Range” as well
Please let me know for any doubts. I would be happy to discussmore in details.