If incubation periods are 6,6,8,8,8,10,10 days, what is the mean incubation period?

• A. 6 days
• B. 7 days
• C. 8 days
• D. 9 days

Answer: (C)

Compute the mean by adding all incubation times and dividing by how many observations there are. The values are 6, 6, 8, 8, 8, 10, 10. Their sum is 56, and there are seven observations, so 56 divided by 7 equals 8. The mean incubation period is 8 days. This dataset also centers around 8, since 8 occurs most often (mode) and lies at the middle value when the data are ordered (median), illustrating the central tendency of the data.