The mean age of the singers in a children's choir is 13.2 years. A 6-year-old
joins the choir. Which sentence is true?
A. The mean age is still 13.2 years.
OB. The new mean age is 9.6 years.
OC. The new mean age is less than 13.2 years.
OD. The new mean age is greater than 13.2 years.