Statistical Inference two types: 1. Estimating the value of a parameter with a confidence interval. 2. Assessing
evidence for a claim about a parameter using a test of significance.
We get Margin of Error (ME) from the sampling distribution of
.
Condition: 1. SRS(stratified, multistage are wrong!) 2.σ is known. 3. Sampling distribution of
is normal.
Level of confidence: the percentage of confidence intervals that could be produced by the procedure that actually
contain the value of μ. Since the procedure of using (
ME,
+ME) to estimate μ gives intervals that contain μ
for 95% of all possible
values, we say: level of confidence is 95%. (Note: This can only be defined in terms of
probability as follows: “The probability that the confidence interval to be computed (before data are gathered) will
contain the value of the parameter.” After data are collected, level of confidence is no longer a probability because a
calculated confidence interval either contains the value of the parameter or it doesn’t.)
Multiple analyses: Performing two or more tests of significance on the same data set. This inflates/ amplifies the
This is the end of the preview.
Sign up
to
access the rest of the document.
 Winter '11
 PattiColling
 Statistics, Normal Distribution, Parameter Value

Click to edit the document details