Determine the critical value. Remember:
When estimating the mean, if the population standard deviation
(σ) is known, use z.
When estimating the proportion, use z.
Find z using = -norm.s.inv((1-confidence
level)/2)
When estimating the mean, if the population standard deviation
(σ, sigma) is unknown--meaning that you have a sample standard
deviation (s)--use t.
Find t using =t.inv.2t(1-confidence level, n-1)
Group of answer choices
Estimating the mean at 95% confidence, n=25, s=4.5
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