Question

Harry and Ron decide to investigate the average number of hours Hermione spends in the library weekly for their fourth year.

1. if they record information for the entire year, would they find a population parameter or a sample statistic? What notation is appropriate?

2. If they give up after the third week, would this be a sample static or a population parameter? What notation is appropriate?

3. What is meant by 95% confidence?

Answer 1

1:- If they record information for the entire year then it would be population parameter.

i.e And the Notation is μ

μ is used for population Mean.

2:- If they give up after the third week, then it would be Sample parameter.

And the Notation is x̄

x̄ is used for Sample mean

3 :- 95 % Confidence   

95 % Confidence means that the true population mean value is   lies between the lower limit and upper limit of the 95 % interval..i.e. an interval with a 0.95 probability of containing the population mean.

Mean there is 0.95 probability that the population mean is between that interval.

Only 5 % Chance that the population mean has different value than the interval .