The mean of the sample is called a point estimator. It provides a single point or value as an est of the pop parameter.
is a statistic that has a sampling distribution with a mean exactly equal to the pop parameter being used.
is a range of values constructed to have specific probability of including the pop parameter, the mean.
The greater the confidence level (1-alpha) , the greater the probability that the interval will actually include (mue)
95% Confidence level-
1. alpha - .05 - cv= 1.96 nondirectional
2. better level due to the width of the interval being.
3. .05 the the interval will miss the mue
99% Confidence level-
1. alpha - .01 - cv= 2.58
2. less precise due to the large width of the interval.
3. .01 will miss the inteval.
Size of St. Error of the Mean.
1. as the st. error decre, so does the width of the confidence interval.
2. Incre in n results in more information confidence interval.