Question
In: Statistics and Probability
A random sample of 90 observations produced a mean of 32.4 from a population with a...
A random sample of 90 observations produced a mean of 32.4 from a population with a normal distribution and a standard deviation ?=2.98.
(a) Find a 90% confidence interval for μ
≤?≤
(b) Find a 95% confidence interval for μ
≤?≤
(c) Find a 99% confidence interval for μ
≤?≤
Solutions
Expert Solution
a) Z for 90% confidence interval = Z0.05 = 1.645
Confidence interval 
= (31.883 < µ < 32.917)
b) Z for 95% confidence interval = Z0.025 = 1.96
Confidence interval 
= (31.784 < µ < 33.016)
c) Z for 99% confidence interval = Z0.005 = 2.576
Confidence interval 
= (31.591 < µ < 33.209)
orchestra answered 1 year agoRelated Solutions
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