If x represents the side length of the square cut from each corner, then the dimensions of the base of the box are 26-2x by 43-2x. The volume of the box is
... V = x(26-2x)(43-2x)
where x is restricted to the domain 0 ≤ x ≤ 13.
Plotting this equation using a graphing calculator shows the maximum volume to be 2644.7 in³.
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The analytical solution can be found by setting the derivative of V to zero.
... V = 4x³ - 138x² +1118x
... dV/dx = 0 = 12x² -276x +1118
This has solutions given by the quadratic formula, where a=12, b=-276, c=1118:
... x = (-b±√(b²-4ac))/(2a)
The plus sign will give a solution that is not in the allowed domain of x, so the only viable solution is the one where the radical is subtracted.
... x = (276 - √(76176--53664))/24 = (23/2) - √(469/12) ≈ 5.2483 . . . inches
Then the corresponding maximum volume is found from the equation for V.
... V ≈ (5.2483)(26 - 2·5.2483)(43 - 2·5.2483) ≈ 2644.6877 in³ . . . . as above
Answer:
(e) the mean number of siblings for a large number of students has a distribution that is close to Normal.
Step-by-step explanation:
Central Limit Theorem
The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean and standard deviation , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean and standard deviation .
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
By the Central Limit Theorem
The sampling distributions with a large number of students(at least 30) will be approximately normal, so the correct answer is given by option e.
Answer:
1 1/8
Step-by-step explanation:
Answer:
B you still use the same amount of water in the dishwasher when you run it full of dishes as when you run it half full of dishes
Step-by-step explanation:
Answer:
B: 610; A: 202,000
D: 253; C: 2,007,000
Step-by-step explanation:
These are all expressions that can be calculated as is, or that can be simplified a little bit by taking advantage of the distributive property and other properties of addition and multiplication. The idea is to look for numbers that show up more than once, and rearrange the expression so they only show up once.
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<h3>B = (597 -176) +(13 +176)</h3>
This is a straight addition problem. The two "176" values have opposite signs, so cancel when they are added. Using the associative and commutative properties of addition, we can rearrange this to ...
597 +13 +(-176 +176)
= 597 +13
This can further be rearranged to ...
= (597 +3) +(13 -3)
= 600 +10
= 610
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<h3>A = 2020×173 -2020×73</h3>
The factor 2020 can be put outside parentheses using the distributive property:
= 2020(173 -73)
= 2020×100
= 202,000
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<h3>D 17×15 -15 +13</h3>
The value 15 is repeated. Terms using it can be combined using the distributive property.
= 15(17 -1) +13
= 15(16) +13
= 240 +13
= 253
Another way to look at this one is to use the factoring of the difference of squares.
= (16 +1)(16 -1) +(-15 +13)
= 16² -1² +(-2)
= 256 -3
= 253
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<h3>C 2019×890 -(12000 -2019×110)</h3>
Again, we can focus on rearranging so 2019 only needs to show up once.
= 2019(890 +110) -12000
= 2019×1000 -12×1000
= (2019 -12)×1000
= 2,007,000