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Bill Alther is a zoologist who studies Anna\'s hummingbird ( Calypte anna ).† Su

ID: 3323594 • Letter: B

Question

Bill Alther is a zoologist who studies Anna's hummingbird (Calypte anna).† Suppose that in a remote part of the Grand Canyon, a random sample of six of these birds was caught, weighed, and released. The weights (in grams) were as follows.

The sample mean is x = 3.75 grams. Let x be a random variable representing weights of hummingbirds in this part of the Grand Canyon. We assume that xhas a normal distribution and = 0.96 gram. Suppose it is known that for the population of all Anna's hummingbirds, the mean weight is = 4.70 grams. Do the data indicate that the mean weight of these birds in this part of the Grand Canyon is less than 4.70 grams? Use = 0.10.

(a) What is the level of significance?

What is the value of the sample test statistic? (Round your answer to two decimal places.)


(c) Find (or estimate) the P-value. (Round your answer to four decimal places.)

3.7 2.9 3.8 4.2 4.8 3.1

Explanation / Answer

The statistical software output for this problem is:

One sample Z summary hypothesis test:
: Mean of population
H0 : = 4.7
HA : < 4.7
Standard deviation = 0.96

Hypothesis test results:

Hence,

a) Level of significance = 0.10

b) Sample test statistic = -2.42

c) P - value = 0.0077

Mean n Sample Mean Std. Err. Z-Stat P-value 6 3.75 0.39191836 -2.4239742 0.0077