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Use the appropriate alphabet (a, b, c, d, etc) to indicate your answer for each

ID: 3226026 • Letter: U

Question

Use the appropriate alphabet (a, b, c, d, etc) to indicate your answer for each question To determine the distribution mode of a certain species of crickets, 200 quadrats were randomly established in a fields known to be their habitat. The number of crickets found in each quadrat is recorded in the frequency distribution below? a. From the data calculated for problem 1, were the crickets randomly distributed over the 200 quadrats. You must show proof to obtain credit. b. What is the probability of walking into that field and seeing a cricket?

Explanation / Answer

We have randomly chosen 200 quadrats. If the crickets is uniformly distributed over the 200 quadrats, we would expect the count to be equal among the quadrats. We need to carry out the regular chi-square test for four cells 0-3 having a frequency equal to 200/4 = 50

> tt <- c(98,52,28,22)
> names(tt) <- 0:3
> tt
0 1 2 3
98 52 28 22
> chisq.test(tt)

        Chi-squared test for given probabilities

data: tt
X-squared = 71.52, df = 3, p-value = 2.017e-15

The chi-square result shows that the distribution is not uniform.