A survey was completed by 446 students in introductory statistics courses at a large university in the fall of 2003. Students reported whether or not they had pierced ear(s).
a. Use software to access the survey data and produce a 95% confidence interval for the proportion of all students with pierced ear(s), assuming the surveyed students were a representative sample.
b. Does your interval contain 0.50?
c. Test whether the proportion with pierced ear(s) in the larger population from which surveyed students were sampled could equal 0.50; report the z statistic.
d. Draw your conclusions, using 0.05 as the cutoff for a small P-value.
e. Explain how your answers to parts (b) and (d) are consistent with one another.
f. Would sample proportion be higher or lower if only females were surveyed?
g. Would standardized sample proportion z be higher or lower if only female students were surveyed?
h. Would the P-value be larger or smaller if only female students were surveyed?