Help me please I need it

A box of volume 180 m3 with square bottom and no top is constructed out of two different materials. The cost of the bottom is $4

zysi [14]

Answer:

Side of square bottom=6.46 m

Height of box=4.31 m

Step-by-step explanation:

Let s be the side bottom

Height of box=h

Volume of box= $180m^3$

Volume of box= $lbh=s^2h$

$s^2h=180$

$h=\frac{180}{s^2}$

Cost of bottom=$40 per square m

Cost of sides =$30 per square m

Total cost= $C=40s^2+30(4sh)$

$C=40s^2+120s\times \frac{180}{s^2}$

$C(s)=40s^2+\frac{21600}{s}$

Differentiate w.r.t s

$C'(s)=80s-\frac{21600}{s^2}$

$C'(s)=0$

$80s-\frac{21600}{s^2}=0$

$80s=\frac{21600}{s^2}$

$s^3=\frac{21600}{80}=270$

$s=(270)^{\frac{1}{3}}=6.46$

Again,differentiate w.r.t s

$C''(s)=80+\frac{43200}{s^3}$

Substitute s=6.46

$C''(6.46)=80+\frac{43200}{(6.46)^3}=240.2>0$

Hence, the cost is minimum at s=6.46

$h=\frac{180}{s^2}=\frac{180}{(6.46)^2}=4.31$

Side of square bottom=6.46 m

Height of box=4.31 m

5 0

3 years ago

Help with #12, 13, 14, 15! I will mark u as brainliest answer

son4ous [18]

12) LCM of 2 & 12 is 12
Answer: (F)

13) (25 x 8) x 4
Step 1: Order of operations do parenthesis first: (25 x 8) = 200
Step 2: Multiply: 200 x 4 = 800
Answer: 800

14) I would plug each value in to see which works
D) 10x + 5y = 10(6) + 5(9) = 60 + 45 = 105

Answer is (D)

15) 2 x 12 - 8 (divided by) 2^2
Exponent first: 2 x 12 - 8 divided by 4
Multiplication/ Division: 2 x 12 = 24 and -8 divided by 4 = -2
Add/Subtract: 24 - 2 = 22

Answer: (I)

7 0

4 years ago

Suppose I have a wooden cube, which I then split into eight equal pieces. If I give you two of those pieces, and then give you t

vampirchik [111]

Answer:

.625

Step-by-step explanation:

Since the amount of pieces are 8, and you gave 5 away, you have to divide 5 by 8. This gives you .625

5 0

3 years ago

Read 2 more answers

When a distribution is mound-shaped symmetrical, what is the general relationship among the values of the mean, median, and mode

yuradex [85]

Answer:

The mean, median, and mode are approximately equal.

Step-by-step explanation:

The mean, median, and mode are central tendency measures in a distribution. That is, they are measures that correspond to a value that represents, roughly speaking, "the center" of the data distribution.

In the case of a normal distribution, these measures are located at the same point (i.e., mean = median = mode) and the values for this type of distribution are symmetrically distributed above and below the mean (mean = median = mode).

When a distribution is not symmetrical, we say it is skewed. The skewness is a measure of the asymmetry of the distribution. In this case, the mean, median and mode are not the same, and we have different possibilities as the mentioned in the question: the mean is less than the median and the mode (negative skew), or greater than them (positive skew), or approximately equal than the median but much greater than the mode (a variation of a positive skew case).

In the case of the normal distribution, the skewness is 0 (zero).

Therefore, in the case of a mound-shaped symmetrical distribution, it resembles the normal distribution and, as a result, it has similar characteristics for the mean, the median, and the mode, that is, they are all approximately equal. So, the general relationship among the values for these central tendency measures is that they are all approximately equal for mound-shaped symmetrical distributions, considering they have similar characteristics of the normal distribution, which is also a mound-shaped symmetrical distribution (as well as the t-student distribution).

5 0

3 years ago

Represent the following expression algebredically: a number, x, decreased by 5

PIT_PIT [208]

X-5 is your answer. hope that helps

5 0

3 years ago