Question $11$:$$ Where possible, using the improved line listing, calculate incubation periods and $$ illustrate their distribution with an appropriate graph $($using Excel or any other graphing software$).$ Remember, you can only calculate incubation periods for persons who gave a $$Time of Meal$.$ Use $(1)/(2)$ hour increments on the x$-$axis.

Question $12$:$$ What is the range $($include minimum and maximum$),$ the mean, the mode, and the median of the incubation periods.

Question $13$:$$Using the information on incubation period, combined with the data on clinical symptoms, conduct a differential diagnosis of the illness and name the agent you believe is responsible for this outbreak?$$ You have enough information to answer with only one $(1)$ agent. Explain your answer. $($Please refer to the Compendium of Acute Foodborne Gastrointestinal Disease to identify the most likely agent of infection$).$