Q 11

If the expected value of a sample mean equals the population mean,the sample mean is biased.

Q 12

For any sample size n,the sampling distribution of is normal if the population from which the sample is drawn is uniformly distributed.

Q 13

For any population X with expected value µ and standard deviation σ,the sampling distribution of will be approximately normal if the sample size n is sufficiently small.As a general guideline,the normal distribution approximation is justified when n < 30.