A random sample ofn

measurements was selected from a population with standard deviation=19.6

and unknown mean

. Calculate a99

% confidence interval for

for each of the following situations:

(a)n=50,x

=104.3

(b)n=75,x

=104.3

(c)n=105,x

=104.3

(d) In general, we can say that for the same confidence level, increasing the sample sizethe margin of error (width) of the confidence interval. (Enter: ''DECREASES'', ''DOES NOT CHANGE'' or ''INCREASES'', without the quotes.)