Posted by Alex on .
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.

Math(Probability) 
PsyDAG,
90% = mean ± 1.645 SEm (Standard Error of the mean)
SEm = s/√(n1)
I'll let you do the calculations.