A specific numerical value estimate of a parameter. The best point estimate of the population mean μ is the sample mean x̄.
An interval or a range of values used to estimate the parameter.
A range of values constructed from sample data so that parameter occurs within that range at a specified probability. The specified probability is called the level of confidence.
The maximum likely difference between the point estimate of a parameter and the actual value of the parameter.
Minimum sample size needed for an interval estimate of the population mean, when n ≥ 30.
|
Situation |
n ≥ 30 | n < 30 σ known |
n < 30 σ unknown |
|
Test |
Z |
Z |
t |
| CI |
 |
 |
|
When testing for = or ≠, α need to be divided by 2.
Thus, Zα/2 are used. Otherwise, use Zα.
If σ is unknown, replace by s.
An interval or a range of values used to estimate the parameter.
An interval or a range of values used to estimate the parameter.
An interval or a range of values used to estimate the parameter.