SOLUTION: You measure 22 textbooks' weights, and find they have a mean weight of 73 ounces. Assume the population standard deviation is 12.9 ounces. Based on this, construct a 90% confidence

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Question 1177941: You measure 22 textbooks' weights, and find they have a mean weight of 73 ounces. Assume the population standard deviation is 12.9 ounces. Based on this, construct a 90% confidence interval for the true population mean textbook weight.
Give your answers as decimals, to two places
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!

Hi
Normal Distribution: σ = 12.9
Sample:  n = 22, x̄ = 73
90% confidence interval: two-sided(df= 21), t = 1.72
ME =+z%2Asigma%2Fsqrt%28n%29
ME =+1.72%2A12.9%2Fsqrt%2822%29 = 4.7
73 - 4.7< mu < 73 + 4.7
CI: ( 68.3, 77.7) 

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