Answer:
The new mean is 77cm
Step-by-step explanation:
If the mean height of the 30 children in a room is 76 cm, then the sum of their ages is

If James with height 107cm joins them, then the total number of children now becomes 30+1=31 and the total height becomes: 2280cm+107cm=2387cm
The new mean now becomes:

So hmmm check the graph below
now.. to find the vertex of any quadratic

so... how long did it take? well, it took

what was the highest point? well, it was

when did he hit the water? well, at y = 0
that is

solve for "t"
The reciprocal of -1/3 is -3/1
and the reciprocal of 4/1 is 1/4
the sum of the expanded angle is 180⇒

I think that the answer is 2400. hope it help???