In: Statistics and Probability
a) Explain the difference between a statistic and a parameter.
b) Is it possible to calculate a parameter? Why or why not?
c) Can you trust a statistic? Explain.
d) Will statistics change from one sample to another? Why or why not?
a) The fundamental difference between statistic and parameter is that :
Statistic is calculated based on sample values and parameter is calculated based on population values.
b) Parameters can be calculated . Suppose we have a population data of weight of students in a classroom. we can calculate the variance of this data , which is a parameter . But note that parameter is constant , it cannot be changed .
c) Yes , if the sample , based on which the statistic is calculated ,is good enough ( random , large etc.) then we can trust statistic as representative of paramater .It totally depends on the sample .
d) Obviously statistic will change its value the moment we change the sample , because it is based only on sample values .