Answer:
2.5
Step-by-step explanation:
The positive factors of 12 are 1,2,3,4,6,12
The positive prime factors of 12 are 2 and 3.
(Primes are integer numbers only divisible by themselves and one.)
The arithmetic mean or average of 2 and 3 is (2+3)/2.
(2+3)/2=5/2=2.5
