When you calculate confidence interval with a sample size, something problematic might occur. If you do them in groups of 1000, 990 of the individuals will have the results, and so on. These levels of confidence tell us if you make the research over groups of 100, 99 of the individuals in these groups will have the same result.
That will, again, mean you can be 99% sure that the confidence interval of your sample size contains the population means. If you want to be more definite you can calculate a 99% confidence interval.
That means you can be 95% sure that the confidence interval from the sample contains the population mean. Instead, you choose a small group of people that you think represent the whole population best work from there.Īnother good thing about confidential intervals is that you can calculate depending on how much you want to be sure of your results. It is impossible to track down every runner in the country and ask them their reviews on this app. For example, you are designing a new running app for runners. So instead you pick a smaller group you believe represents our whole population the best and make our calculations based on that group. When you are making researches on large groups it is really hard to collect data from each individual in this population in terms of time and resources.