Question 769233
Estimates of the earth's biomass, the total amount of vegitation held by the earth's forests, are important in determining the amount of unabsorbed carbon dioxide that is expected to remain in the earth's atmosphere. Suppose a sample of 75 one-square-meter plots, randomly selected in North America's boreal forests, produce a mean biomass of 4.2 kilograms per square meter with a standard deviation of 1.5 kilograms per square meter. Estimate the average biomass for the boreal forests of North America and find the margin of error for your estimate 
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sample mean:: 4.2 kg
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Assuming you want 95% confidence you get::
ME = 1.96*(1.5/sqrt(75)) = 0.8591
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Cheers,
Stan H.
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