Question

Allen's Hummingbird has been studied by zoologist Bill Alther. Suppose a small group of 14 Allen's Hummingbirds has been under study in Arizona. The average weight for those birds is x = 3.15 grams. based on previous studies, we can assume that the weights of Allen's Hummingbirds have normal distribution = 0.32 gram.

A) Find an 80% confidence interval for the average weights of Allen's Hummingbirds in the study region. What is the margin of error? Round to 2 decimal places.
- Lower Limit _______
- Upper Limit _______
- Margin of Error _________

B) What conditions are necessary for your calculations? (Select all that apply)
- Normal Distribution of Weights
- n is Large
- ¤ is unknown
- ¤ is known
- Uniform distribution of weights

C) Interpret your results in the context of the problem.
- There is a 20% chance that the interval is one of the intervals containing the true average weight of the Hummingbirds in this region.
- The probability to the true average weight is equal to the mean
- The probability that this interval contains the true average weight is 0.80.
- There is an 80% chance that the interval is one of the intervals containing the true average weight of the Hummingbirds in this region.

D) Find the sample size necessary for an 80% confidence level with a maximal margin error E = 0.06 for the mean weights of Hummingbirds. Round to the nearest whole number.
_________ hummingbirds.

Answer 1