Answer:
A) .9423
Step-by-step explanation:
The chance of getting at most 13 heads is 0.9423
V=lwh, so try to solve it that way.
4(4x+10)=360
16x+40=360
-40 -40
16x=320
÷16 <span> ÷16
</span>
x=20
The base will have the greatest area for a given perimeter if it is square. If the edge of the square base has length x (in feet), then the total material requirement in square feet is
.. m = x^2 +(4/x^2)*(4x)
.. m = x^2 +16/x
This will have a minimum where dm/dx = 0.
.. dm/dx = 2x -16/x^2 = 0
.. x^3 = 8 . . . . . . . . . . . . . . . multiply by x^2/2 and add 8
.. x = 2
The tank is 2 feet square and 1 ft high.
_____
You will note that it is half the height of a cube that has double the volume. This is the generic solution to all minimum cost open-top box problems. Actually, the costs of pairs of opposite sides are equal to each other and to the cost of the base. If material costs are not identical in all directions, that is the more generic solution.
If you would like to know which pair of measurements is not equivalent, you can calculate this using the following steps:
1 yard = 3 feet
1 foot = 12 inches
1 mile = 5280 feet
8 yards = 8 * 3 feet = 24 feet
2 feet = 2 * 12 inches = 24 inches
10 feet = 10 * 12 inches = 120 inches
3 miles = 3 * 5280 feet = 15,840 feet
Not equivalent: <span>3 miles, 15,480 feet.</span>
