How can scientists compare two different populations

scientists compare two different populations, To test and estimate the difference between two populations, scientists take out random samples from the each of two population and then they consider those samples individually and try to find that how each sample is different from another sample.

The samples of two groups are assumed to be independent, the common use of this comparison between two different populations is an experimental response on two different populations.

it also supports my hypothesis. if you rest first you can squeeze the clothespin more times. from the data i collected the average of the eight people concluded exercise makes your muscles more fatigued and less able to squeeze the clothespin compared to resting before squeezing.