A television sports commentator wants to estimate the proportionof citizens who? "follow professional? football." Complete parts?(a) through? (c).
?(a) What sample size should be obtained if he wants to bewithin
44
percentage points with
9494?%
confidence if he uses an estimate of
4848?%
obtained from a? poll?The sample size is
nothing.
?(Round up to the nearest? integer.)?(b) What sample size shouldbe obtained if he wants to be within
44
percentage points with
9494?%
confidence if he does not use any prior? estimates?The samplesize is
nothing.
?(Round up to the nearest? integer.)
?(c) Why are the results from parts? (a) and? (b) so? close?
A.The results are close because the margin of error
44?%
is less than? 5%.
B.The results are close because
0.48 left parenthesis 1 minus 0.48 right parenthesisequals0.48(1?0.48)=0.24960.2496
is very close to 0.25.
C.The results are close because the confidence
9494?%
is close to? 100%.
