Estimation & Confidence Intervals
Estimation & Confidence Intervals
Now called "point estimate"
Build Confidence Interval around it
Confidence Intervals
General Formula:
[Point estimate ± Margin of Error]
Inferential Theory
σ unknown (t)
σ known (z)
proportion (z)
Considers dispersion, n & α
Why Care?
x̅1 = 100 with range of [5 to 195]
x̅2 = 100 with range of [90 to 110]
Examples
Titleist
Undergrad
Example
Finding Z-value
Finding Z-value
Finding t-value
Example
Example
Example
t-distribution
σ unknown
more conservative (wider interval)
2 components: α/2, df
Factors influencing Confidence Interval Width
vs.
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Constructing C.I.'s
