Each of 13 randomly chosen female registered voters were asked to indicate if she was going to vote for candidate A or candidate B in an upcoming election.The results show that 9 of the subjects preferred A. Is this sufficient evidence to conclude that candidate A is preferred to B by female voters?

(a) Perform the appropriate hypothesis test. Be sure to justify your choice of test.

(b) Derive and interpret a confidence interval for the median with at least a 90% confidence level.

Show all your work to get full points. If your answer only shows R output, without supplementary formulas and necessary statistical analysis, you will get very few points. It is OK to use R to calculate test statistics and p-values. Supplement results from R with equations to calculate the test statistic and p-value. You do not need to do everything by hand. Your answers must be as clear as possible