28 32 21 22 the mean is 24.4 what is the 5th number

65 8 7 4 5 6 8 4 3 2 1 9 5 6 4 2 1 6 5 1 5 1 3 2 3 5 multiply the third number in the first row by the seventh number in the third row. add this result to the fifth number in the second row. add to this total ten times the fourth number in the third row. subtract the eighth number in the first row from the result.

Me n o w. i need t h i s. 10 points

Acertain volume of water contains 100000 hydrogen atoms and 50,000 oxygen atoms how many hydrogen atoms are in a volume of water containing 4 million oxygen atoms