18. Refer to the ordinal scale in Table 6.2. Treat this as a qualitative variable, as follows. Ig- nore the subjects responding in the moderate category. Of the remainder not responding in that category, let denote the population proportion who make one of the three lib- cial responses and let 1 - denote the population proportion making one of the three conservative respouses. Test the hypothesis that these proportions are identical. Find the P-value and interpret.