The University is considering changing the email system that they currently use. Since there are substantial learning costs associated with any new software, the University only wants to change to the...

The University is considering changing the email system that they currently use. Since there are substantial learning costs associated with any new software, the University only wants to change to the new system if it is very confident that there is at least a 20% difference in the proportion of faculty and staff who say they like the new system. In a sample of 139 users of the current system, the University finds that 66 say they like the current system. In another sample of 92 experimental users of the “new” system, the University finds that 73 of them like the new system. When testing the hypothesis (using a 5% level of significance) that there is at least a 20% difference in the proportion of users who like the two systems, what is the test statistic? (please round your answer to 2 decimal places)