>>11494509with this problem, the key to solving it is to look at the pattern of the number of children for each age to give an extremely accurate estimate for the amount of children that are 7 years old. let's write down our sequence with the missing term that we have to find being x and find all of the differences of that sequence.
4 9 x 1 1
+5 +60 -68 +0
+55 -128 +68
-183 +196
+379
now that we know how this sequence changes, we can safely say that x = 69 and that there were 69 7 year olds.
