In a study designed to assess the impact that a fire as on deer behavior and hab
ID: 3150878 • Letter: I
Question
In a study designed to assess the impact that a fire as on deer behavior and habitat, forest ecologists established a 3000 acre study site, part of which had been affected by a major burn 6 months prior. The site was divided into 4 areas: The inner burn area, the inside edge, the outside edge, and the outer area (which had little to no actual fire damage). One of the study questions was whether or not deer showed a preference for one or more areas over the others. The specific acreage for each area is summarized in Table 1. Is there enough evidence to conclude that the deer in this habitat preferred one area over the other? During the course of the study observers recorded a total of 90 deer in the study area. 5 were seen in the inner burn area, 15 were seen in the inner edge area, 28 were seen in the outside edge area, and the rest were seen in the outer area. Let = 0.01.
A) Give the hypothesized distribution of the deer. That is, give the hypothesized proportion of deer for each of the four areas.
Hint: Since the acreage for each area is different, we'd expect to see more deer in the larger areas regardless of preference.
Round all answers to three decimal places.
Inner Burn Area:
Inside Edge:
Outside Edge:
Outer Area:
B) The number of degrees of freedom for this study is:
C) Fill in Table 2, which you will use to find the test statistic. The last column is (observed - expected)2/expected.
Note: Round to 3 decimal places where necessary.
D) What is the test statistic?
E) What is the critical value for this test?
F) Based on your critical value and conclusion, the corresponding decision/conclusion is:
Reject Ho and conclude that deer have no preference.FTR Ha and conclude that deer prefer one area over the others. Reject Ha and conclude that deer have no preference.FTR Ho and do not conclude that deer prefer one area over the others.Reject Ho and conclude that deer prefer one area over the others.Reject Ha and do not conclude that deer prefer one area over the others.
Table 1: Acreage Area Inner Burn Inside Edge Outside Edge Outer Acreage 520 210 240 2030Explanation / Answer
H0: Deer have equal preference for all area
Ha: atleast two areas have different preference
Chi square test two tailed
Contingency table is prepared for expected values and chi square calculated
chi square = 85.17
df = 3
The P-Value is < 0.00001. The result is significant at p < 0.05.
Reject Ho and conclude that deer prefer one area over the others.
Area Inner Burn Inside Edge Outside Edge Outer Acreage 520 210 240 2030 3000 Observed 5 15 28 42 90 Expected 15.6 6.3 7.2 60.9 90 (O-e) -10.6 8.7 20.8 -18.9 (O-e)^2/e 7.202564 12.01429 60.08889 5.865517 85.17126 df 3