# Math(Probability)

posted by Alex

Students took n = 35 samples of water from the east basin of Lake
Macatawa and measured the amount of sodium in parts per million. For their data,
they calculated notation bar x= 24.11 and s^2= 24.44. Find an approximate 90% confidence interval for μ , the mean of the amount of sodium in parts per million.

1. PsyDAG

90% = mean ± 1.645 SEm (Standard Error of the mean)

SEm = s/√(n-1)

I'll let you do the calculations.

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