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.**

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