To find x, we simply need to subtract the sum of the other two sides from 73.
35+11=46
73-46=27
So x = 27mm
3 divided by 8 = 0.375
0.375 x 100 = 37.5%
37.5% is closest to 38%
Since x is the length, then x+7 has to be the width.
The area of a rectangle can be found via the formula :
A = length * width
So if we replace the area with the given number (170) and the length, and width, with what we assumed, we get..
170 = x * (x+7)
[which is.. ]
170 = x^2 +7x
0 = x^2 +7x - 170
And that is the answer.
They will require between 18.42 and 31.58 minutes.
We want the middle 90%. The two probability values associated with this would be 0.95 and 0.05; this would leave 5% below and 5% above, giving us the middle 90%.
Using a z-table (http://www.z-table.com) we see that the z-score associated with an area to the left of 0.05 is between -1.64 and -1.65; since it is equally distant from both we will use -1.645.
The z-score associated with an area of the left of 0.95 is between 1.64 and 1.65; since it is equally distant from both we will use 1.645.
The formula for a z-score is
z = (X-μ)/σ
-1.645 = (X-25)/4
Multiplying by 4 on both sides,
-1.645(4) = X-25
-6.58 = X-25
Adding 25 to both sides,
-6.58+25 = X
18.42 = X
For the upper bound,
1.645 = (X-25)/4
Multiplying both sides by 4,
1.645(4) = X-25
6.58 = X-25
Adding 25 to both sides,
6.58+25 = X
31.58 = X
The times are between 18.42 and 31.58 minutes.
A. V=240
10x6x4=240
B. V= 1194.59
n(pie) 6.5x9
C. V= 6171.67
D. V= 1603.52
E. V=6859
