Question

Is it true that (yes/ no, and why?):

a) Once we know the mean of the population we can derive the mean of any sample from this population

b) Once we know the mean of a sample, the population mean can be calculated?

c) Chi-square test is one-tailed

d)Is statistically significant difference an indicator that the difference is substantial and large?

e)Is there are always clear reasons for choose p-value decision threshold to avoid any chance of type I error?

Answer 1

a) Not true : Because we don't know anything about the population mean. We have to estimate it using the sample mean.

b) True : Yes once we know the sample mean, we can estimate the population mean. Because sample mean is an unbiased estimator of population mean.

c) Not true : Because chi square test is left tail, right tail and both tails also. Hence chi square test is not only one tail.

d) Not true : Because, statistically significant diference do not indicate that the difference exactly substantial and large. The difference may be small or large. We can't predict anything about the difference from significant difference.