4.Lab_Problems

# 4.Lab_Problems - lake with a 95% confidence level? 3. The...

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Lab 4 : Confidence Intervals and Sample Size Geog306, Spring 2007 Name: Concentrations: Confidence Interval for Mean 1. A biogeographer weighed a random sample of 30 hedgehogs. She found that the mean weight of the sample was 0.885kg and the standard deviation was 0.096kg. Find a 90% confidence interval for the mean of the entire population of hedgehogs. 2. Suppose that we check for clarity in 50 locations in Lake Tahoe and discover that the average depth of clarity of the lake is 14 feet with a standard deviation of 2 feet. What can we conclude about the average clarity of the
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Unformatted text preview: lake with a 95% confidence level? 3. The built-in data set LakeHuron records annual measurements of the level of the lake. Find a 95% confidence interval for the true mean lake level. Sample Size for mean estimate 4. Suppose you want to estimate the mean yield of corn per acre to significance level of 95%. A preliminary sample of 50 acres found the mean to be 74 bushels and with a standard deviation of 16.65 bushels. How many acres do you need to sample in order to be within 3% of the true mean?...
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## This note was uploaded on 04/18/2008 for the course GEOG 306 taught by Professor Yeo during the Spring '08 term at Maryland.

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