Answer: Noah is right. If the mean for the second lake is 60ft and the first lake is 45ft, the second lake has an average depth that is 15 feet deeper.
The standard deviations also indicate that the second lake has some even deeper spots, and even the shallower spots of the second lake are about the same as the shallow spots of the first lake.
Step-by-step explanation:
-- The area of the long skinny piece on top is (6 x 33) = 198
-- The length of the dotted line between the top and bottom pieces is (33-21) = 12
-- The area of the bottom piece is (12 x 15) = 180
-- The area of the whole thing is (198 + 180) = 378
-- The perimeter of the whole thing is (33 + 6 + 21 + 15 + 12 + 15 + 6) = 108
So even postive integers are by defention in form 2k where k is a natural number so
let the sum of even integers to n=S
S=2(1+2+3+4+5+6+7+8+......+k-1+k
divide bith sides of equation 1 by 2
0.5S=1+2+3+4+5+...........+k-1+k
S=2(k+(k-1)+..............................+2+1)
divide both sides of equation 2 by 2
0.5S=k+k-1+..............................+2+1)
by adding both we will get
___________________________
S=(k+1)(k)
so the sum will be equal to
S=

so let us test the equation
for the first 3 even number there sums will be
2+4+6=12
by our equation 3^2+3=12
gave us the same answer so our equation is correct
Circumference is equal to pi•d soo...
c = pi•12
= 37.699
Therefore the circumference is approximately 37.7 inches.