Question

As the variance decreases, the power of a significant test……. As the sample size decreases, the power of a significance test _________

Distinguish between a parameter and a statistic?

What is the relationship between the Z and t distribution?

Answer 1

a)

Answer:-

As the variance decreases, the power of a significant test larger.

As the sample size decreases, the power of a significance test decreases.

b)

Answer:-

A statistic and a parameter are very similar. They are both descriptions of groups, like “50% of dog owners prefer X Brand dog food.” The difference between a statistic and a parameter is that statistics describe a sample. Aparameter describes an entire population

c)

Answer:-

z-tests are used when we have large sample sizes (n > 30), whereas t-tests are most helpful with a smaller sample size (n < 30). Both methods assume a normal distribution of the data, but the z-tests are most useful when the standard deviation is known.