Errors in medical prescriptions occur and a study 1 examined whether electronic prescribing may help reduce errors. Two groups of doctors used written prescriptions and had similar error rates before the study. One group switched to e-prescriptions while the other continued to use written prescriptions, and error rates were measured one year later. The results are given in Table 1.
Electronic Written
Error 254 1478
No Error 3594 2370
Total 3848 3848
Find a 99% confidence interval for the difference in the two proportions,Pw - Pe , where Pw is the proportion of errors using written prescriptions and Pe is the proportion of errors using e-prescriptions.
The 99% confidence interval is ? to ?
Is it plausible that there is no difference?