Two different researchers measured the weight of two separate samples of ruby-throated hummingbirds form the same...
Two different researchers measured the weight of two separate samples of ruby-throated hummingbirds form the same population. Each calculated a 95% confidence interval for the mean weight of these birds. Researcher 1 found the 95% confidence interval to be 3.02g < mu < 3.33g, while Researcher 2 found the interval to be 3.15g < mu < 3.62g.
1. What were the sample means for Researcher 1 and for Researcher 2? On what did you base your answer? Explain.
2. Which researcher most likely had the larger sample size? How did you decide? Can you be certain about your answer? Explain why or why not.
Homework Answers
1. Let us find out sample mean for both the Researcher
Researcher 1 
Researcher 2 
2. As we know increasing the sample size decreases the width of confidence intervals, because it decreases the standard error.
So width for Researcher 1 is 3.33-3.02=0.31 and for Researcher 2 width is 3.62-3.15=0.47
Hence Researcher 1 have larger sample size as width of Researcher 1 is smaller than Researcher 2.
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