In: Statistics and Probability
Senario: You are watching a group of children run relay races. You would like to determine the speed of that the children run. You select 30 children and time them in their relay races.
e) What is the parameter for the study?
f. What is the statistic for the study?
g. Is the study an experiment or an observational study?
h. For the study, should you use a proportion or an average?
e) Parameter for the study is total number of childern.
Parameter is a summary number which describes the entire population. Here, the population is group of childern. So, total number of childern would be the parameter of the study.
f) Statistic for the study is speed of childern.
Here, we have notes time taken by 30 children in relay races. So this time noted would be our variable.
Any function of variable is called statistic. In this case, we are interested in speed of children. So, the speed would be our statistic.
g) This is an observational study.
Here, group of children is already running. We are watching them. We just wonder by how much speed they are running. So, this is observational study.
In experiment, we are interested in finding a thing and we perform some actions regarding it. Here, we are not performing anything.
h) For the study, we should use average.
If we want to compare two or more grops or we want study particular fraction of population, then we will use proportion. But in this case, we are interested in finding running speed of group of childern. So, average would be a better descriptive statistic.