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Utku Suleymanoglu (UMich) Interval Estimation s
√ n is estimated
9 / 17 Interval Estimation of Population Mean Student’s t-distribution is another continuous probability distribution.
It looks a lot like the standard normal distribution with symmetricity and mean at
It has a single parameter, called its degrees of freedom. As df increases, it converges
to N (0, 1).
We will rely on another table to calculate probabilities for it. Utku Suleymanoglu (UMich) Interval Estimation 10 / 17 Interval Estimation of Population Mean Utku Suleymanoglu (UMich) Interval Estimation 11 / 17 Interval Estimation of Population Mean CI for µ, Case 2: Normal Population, σ unknown
If population has a normal distribution and σ is unknown, but sample standard
deviation,s , is known, a 100(1 − α)% conﬁdence interval for µ can be constructed via:
x ± tα/2,n−1 s / n
where tα/2,n−1 is t-value with n − 1 degrees of freedom and α/2 upper tail probability.
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This note was uploaded on 03/17/2014 for the course ECON 404 taught by Professor Staff during the Spring '08 term at University of Michigan.
- Spring '08