Answer:
22
Step-by-step explanation:
mean is calculated as
mean = [tex]\frac{sum}{count}[/tex]
Given the mean of 12 numbers is 20 , then
[tex]\frac{sum}{12}[/tex] = 20 ( multiply both sides by 12 )
sum = 240
Given the mean of 8 numbers is 25 , then
[tex]\frac{sum}{8}[/tex] = 25 ( multiply both sides by 8 )
sum = 200
Total sum of the 20 numbers = 240 + 200 = 440, then mean of 20 numbers is
mean = [tex]\frac{440}{20}[/tex] = 22
