In each of parts (a)–(c), we have given a likely range for the observed value of a sample proportion pˆ. Based on the given range, identify the educated guess that should be used for the observed value of pˆ to calculate the required sample size for a prescribed confidence level and margin of error.
a. 0.2 to 0.4
b. 0.2 or less
c. 0.4 or greater
d. In each of parts (a)–(c), which observed values of the sample proportion will yield a larger margin of error than the one specified if the educated guess is used for the sample-size computation?