Answer:
22
Step-by-step explanation:
mean is calculated as
mean = 
Given the mean of 12 numbers is 20 , then
= 20 ( multiply both sides by 12 )
sum = 240
Given the mean of 8 numbers is 25 , then
= 25 ( multiply both sides by 8 )
sum = 200
Total sum of the 20 numbers = 240 + 200 = 440, then mean of 20 numbers is
mean = 
= 22
Scientific notation is the way that scientists easily handle very large numbers or very small numbers. For example, instead of writing 0.0000000056, we write 5.6 x 10-9.
So, if we are dealing with 965000000000000, then the answer would be:
9.65 x 10^14
UMMMMMMMMMMMMMMMMMMMMMMMMM
