SOLUTION: A sample of size 80 from a population having standard deviation σ = 8 produced a mean of 40. The 99% confidence interval for the population mean (rounded to two decimal places

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Question 1054064: A sample of size 80 from a population having standard deviation σ = 8 produced a mean of 40. The 99% confidence interval for the population mean (rounded to two decimal places) is:
The lower limit is

The upper limit is

Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
99% confidence interval
x̄ =40, n = 80 and σ=8
ME = ± +z%2Asigma%2Fsqrt%28n%29, z = invNorm(.995) = 2.576
ME = ± +2.576%2A8%2Fsqrt%2880%29
confidence interval for the population mean ( (rounded to two decimal places)
40 - ME < mu < 40 + ME
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= CI z = value
90% z =1.645
92% z = 1.751
95% z = 1.96
98% z = 2.326
99% z = 2.576