You need more information. If you had the bmi's of every man between 20 and 29 you could get an exact answer. If you had a good sample you could get a good estimate of this answer.
Um, 150000? Don't write this inmetily because it may be wrong.
Step-by-step explanation:
I am only sure about the first one but as for the rest I am not really but I tried...if you need explanations to the first one feel free to ask me
Mean is adding all the numbers then dividing the answer you go from the numbers.