During initial Phase I and II studies, the incidence of nausea and vomiting of a new cancer chemotherapeutic agent was 36% for 190 patients, while 75 control patients receiving conventional therapy experienced nausea and vomiting at a rate of 55%.

a. Is there a significant difference between the incidence of nausea and vomiting between these two drug therapies? Use =0.05. Show both hand calculations and Minitab results.

b. Did the new agent produce a significantly lower incidence of nausea and vomiting? Again use =0.05. Show both hand calculations and Minitab results.