For the right tail, is it appropriate to just calculate a mean and standard deviation, add 1, 2 & 3 standard deviations from the mean to create a range then compare that to the normal 68/95/99.7 for the standard normal distribution after using the norm.dist function in excel to test each standard deviation value.
The contagious period for a cold lasts about three to four days into the illness. As a general rule, people with a cold are most contagious about three days after their initial exposure to the virus. For more information on colds, influenza and related topics, check out the links on the next page.
How Long Do Colds Last? Cold symptoms usually start 2 or 3 days after a person has been exposed to a source of infection. People with colds are most contagious for the first 3 or 4 days after the symptoms begin and can be contagious for up to 3 weeks. Although some colds can linger for as long as 2 weeks, most clear up within a week.