for the 12 months in year 2002

Question

for the 12 months in year 2002 , a police department of a certain province reported 3,4,2,4,9,7,5,2,7,3 and 5 armed robberies. Find the mean armed robberies in a year

Answer 1

The "mean" is just the average; you should have 12 numbers (month seems to be missing in your data).

 

Add up all the numbers and divide by how many there were.  That's the mean.