Hints:  Recall that the Central Limit Theorem tell us that the sampling distribution has mean m and standard deviation sigma/root(n) where m is the population mean, s is the population standard deviation, and n is the sample size.  Also recall that a larger standard deviation indicates a larger probability of a value landing far from the mean.  With n in the denominator, a larger sample size gives a smaller standard deviation. 

Normal Curve with small area shaded to the right because of a small sigma     Normal Curve with Large Standard Deviation Larger Area