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Marina86 [1]
3 years ago
12

"a box is constructed out of two different types of metal. the metal for the top and bottom, which are both square, costs $4 per

square foot and the metal for the sides costs $7 per square foot. find the dimensions that minimize cost if the box has a volume of 30 cubic feet."
Mathematics
1 answer:
jarptica [38.1K]3 years ago
7 0

The base of the box is b ft by b ft and the height is h ft. 
<span>Since the volume is 40 ft³, </span>
<span>h = 40/b² </span>

<span>area of bottom = area of top = b² ft² </span>
<span>area of one side = bh </span>
<span>cost C = 2·4b² + 4·7bh </span>
<span>= 8b² + 28b(40/b²) </span>
<span>= 8b² + 1120/b </span>
<span>dC/db = 16b - 1120/b² </span>

<span>min cost when dC/db = 0 </span>
<span>16b = 1120/b² </span>
<span>b = ∛70 ≅ 4.12 ft </span>
<span>h = 40/b² ≅ 2.36 ft</span>
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Answer:

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Step-by-step explanation:

1) 7+n=-5

7+n-7=-5-7

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3) 3/5x=18

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irinina [24]

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the answer is 28

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As genetic condition affects 8% of the population.

8 % of 10,000

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As, it is also given that, there is an error rate of 1% for condition (i.e., 1% false negatives and 1% false positives).

So, 1% false negatives means out of 800 tested who are found affected , means there are chances that 1% who was found affected are not affected at all.

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So, 1% of 9200 =\frac{1}{100}\times 9200=92

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that is Probability equal to 0.01 or 1%.

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