Cus
Two random samples are dependent if each data value in one sample can be paired with a corresponding data value in the other sample.
A 'random' sample - covers all age groups, genders, and other criteria. A 'targeted' sample might only cover a small part of the population.
stratified sampling, in which the population is divided into classes, and random samples are taken from each class;cluster sampling, in which a unit of the sample is a group such as a household; andsystematic sampling, which refers to samples chosen by any system other than random selection.
There are 25C7 different samples of seven from a pool of 25.25C7 = 25!/(7!(25-7)!) = 480 700 different samples of 7
biased
bias.
Before George Gallup, polling samples were often small and not scientifically selected, leading to biased or unreliable results. Gallup revolutionized polling by using rigorous sampling methods to ensure accurate representation of the population, making his polls more trustworthy and influential.
Data from random samples will not always include the same values. Values are chosen randomly and they may or may not be the same. So means will vary among random samples.
Cus
random
z test
Two random samples are dependent if each data value in one sample can be paired with a corresponding data value in the other sample.
A 'random' sample - covers all age groups, genders, and other criteria. A 'targeted' sample might only cover a small part of the population.
random sampling
There are 324,632 possible samples.
stratified sampling, in which the population is divided into classes, and random samples are taken from each class;cluster sampling, in which a unit of the sample is a group such as a household; andsystematic sampling, which refers to samples chosen by any system other than random selection.