Is there a possibility that two 2 populations have different mean but the same amount of standard deviation?
The comparison of two population means is very common. A difference between the two samples depends on both the means and the standard deviations. Very different means can occur by chance if there is great variation among the individual samples. Notice that the sample variances (s1)2 and (s2)2 are not pooled.
Can you prove that 2 samples come from the same population?
We can never prove the null to be true, just reject it, so these tests cannot really be used to show that 2 samples come from the same population (or identical populations). This is because there could be minor differences in the distributions (meaning they are not identical), but so small that tests cannot really find the difference.
What is the difference between a random sample and a representative sample?
A random sample is a group or set chosen from a larger population or group of factors of instances in a random manner that allows for each member of the larger group to have an equal chance of being chosen. A random sample is meant to be an unbiased representation of the larger population.
How are independent samples from two distinct populations?
Independent samples are simple random samples from two distinct populations. To compare these random samples, both populations are normally distributed with the population means and standard deviations unknown unless the sample sizes are greater than 30. In that case, the populations need not be normally distributed.
Which is the best test for comparing two population variances?
Minitab offers three (3) different methods to test equal variances. The F-test: This test assumes the two samples come from populations that are normally distributed. Bonett’s test: this assumes only that the two samples are quantitative. Levene’s test: similar to Bonett’s in that the only assumption is that the data is quantitative.