Where are the deer? Random samples of square-kilometer plots were taken in different ecological locations of a national park. The deer counts per square kilometer were recorded and are shown in the following table.
Mountain Brush | Sagebrush Grassland | Pinon Juniper |
30 | 20 | 5 |
26 | 63 | 4 |
25 | 22 | 1 |
32 | 22 | 8 |
Shall we reject or accept the claim that there is no difference in the mean number of deer per square kilometer in these different ecological locations? Use a 5% level of significance.
(a) What is the level of significance?
(b) Find SSTOT, SSBET, and SSW and check that SSTOT = SSBET + SSW. (Use 3 decimal places.)
SSTOT | = | |
SSBET | = | |
SSW | = |
Find d.f.BET, d.f.W,
MSBET, and MSW. (Use 2 decimal
places for MSBET, and
MSW.)
dfBET | = | |
dfW | = | |
MSBET | = | |
MSW | = |
Find the value of the sample F statistic. (Use 3 decimal
places.)
What are the degrees of freedom?
(numerator)
(denominator)
c.
Make a summary table for your ANOVA test.
Source of Variation |
Sum of Squares |
Degrees of Freedom |
MS | F Ratio |
P Value | Test Decision |
Between groups | ||||||
Within groups | ||||||
Total |
One factor ANOVA | |||||
Mean | n | Std. Dev | |||
28.3 | 4 | 3.30 | Mountain Brush | ||
31.8 | 4 | 20.85 | Sagebrush Grassland | ||
4.5 | 4 | 2.89 | Pinon Juniper | ||
21.5 | 12 | 16.84 | Total | ||
ANOVA table | |||||
Source | SS | df | MS | F | p-value |
Treatment | 1,758.500 | 2 | 879.25 | 5.808 | .0240 |
Error | 1,362.500 | 9 | 151.39 | ||
Total | 3,121.000 | 11 |
ANSWERS:
(a) α = 0.05
(b) SSTOT = 3121.000, SSBET = 1758.500, SSW = 1362.500
3121.000 = 1758.500 + 1362.500
(c) dfBET = 20, dfW = 9, MSBET = 879.25, MSW = 151.39
(d) F = 5.808
(e) dFN = 2, dfD = 9
(f) Summary table shown above.
Decision: Since the p- value < 0.05, we reject Ho
Conclusion: There is sufficient evidence of a significant difference in the mean number of deer per square kilometer in these different ecological locations.
Get Answers For Free
Most questions answered within 1 hours.