Confidence Intervals (Estimation)

The following elements are essential  for finding confidence intervals:

1.  Critical Number

2. Point Estimate

3. Standard Error

Population                                                                 Sample

m  x(bar) is a point estimate of m x(bar)

s²   s² is a point estimate of s²      s²

s          s is a point estimate of s       s

p   p(hat) is a point estimate of p  p(hat)

Parameters  Point Estimate      Statistics

Confidence Intervals for a Normal Distribution (with sample size (n) greater than or equal to 30)

Population Mean

Difference Between Two Population Means

Population Proportion

Difference Between Two Proportions

Confidence Intervals for a t-distribution (sample size < 30)

Population Mean

Difference Between Two Population Means

Other Confidence Intervals

Population Variance

Difference Between Two Population Variances

Slope of a line for all n

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