In: Statistics and Probability
Use an example to illustrate the difference between parameter, estimator, and estimate.
Sol
Population is descriptive measure that describes a population
An estimator of a population parameter is a random variable that depends on sample information whose value provides an approximation to this unknown parameter
that is sample statistics used to estimate a population parameter is called as estimator
A specific value that obtained from a sample to estimate a population parameter
Suppose we have sample of 6 observation 2,3,4,5,6
parameter here is population mean represented by mu
estimator of population mean is sample mean denoted by xbar
estimate is xbar=sum of values//total values
=2+3+4+5+6/5
=20/5
=4
Example:
Internet sites report that about 13% of Americans are left handed.During a exam , the instructor walks around the room and counts 15 left handed students out of 98 in the class
Here
parameter is population proportion=p=13%=0.13
estimator is sample proportion= p^=x/n
estimate is p^=15/98=0.15306