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4 years ago

Please help 100 points.

Mathematics

2 answers:

IceJOKER [234]4 years ago

7 0

Answer:

76 square feet

Step-by-step explanation:

surface area = 2(wl + hl + hw) w=width h=height l=length

surface area = 2(5*4 + 2*4 + 2*5)

surface area = 2(20 + 8 + 10)

surface area = 2(38)

surface area = 76 square feet

34kurt4 years ago

4 0

Answer:

Step-by-step explanation:

A=2

(width x length+height x length +height x width)

=2·(4·5+2·5+2·4)=76ft^2

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List the first ten multiples of number 4

Dvinal [7]

The First 10 multiples of 4 is:
4
8
12
16
20
24
28
32
36
40

5 0

4 years ago

Read 2 more answers

In selecting a sulfur concrete for roadway construction in regions that experience heavy frost, it is important that the chosen

Lesechka [4]

Step-by-step explanation:

Given - In selecting a sulfur concrete for roadway construction in regions that experience heavy frost, it is important that the chosen concrete has a low value of thermal conductivity in order to minimize subsequent damage due to changing temperatures. Suppose two types of concrete, a graded aggregate and a no-fines aggregate, are being considered for a certain road. The table below summarizes data on thermal conductivity from an experiment carried out to compare the two types of concrete.

Type ni xi si

Graded 42 0.486 0.187

No-fines 42 0.359 0.158

To find - a. Formulate the above in terms of a hypothesis testing problem.

b. Give the test statistic and its reference distribution (under the null hypothesis).

c. Report the p-value of the test statistic and use it to assess the evidence that this sample provides on the scientific question of difference in mean conductivity of the two materials at the 5% level of significance.

Proof -

a.)

Hypothesis testing problem :

H0 : There is significant difference between mean conductivity for the graded concrete and mean conductivity for the no fines concrete.

H1 : There is no significant difference between mean conductivity for the graded concrete and mean conductivity for the no fines concrete.

Test statistic :

$Z = \frac{x_{1} - x_{2} }{\sqrt{\frac{s_{1} ^{2} }{n_{1}} + \frac{s_{2}^{2} }{n_{2}} } }$

$Z = \frac{0.486 - 0.359 }{\sqrt{\frac{0.03496 }{42} + \frac{0.02496 }{42} } }$

$Z = \frac{0.127 }{\sqrt{0.001468}}$

$Z = \frac{0.127 }{0.0377}$

⇒Z(cal) = 3.3687

Z(tab) = 1.96

As Z (cal) > Z(tab)

So, we reject H0 at 5% Level of significance

p-value = 0.99962

Hence

There is significant difference in mean conductivity at the two materials.

5 0

3 years ago

Find the area of each composite figure

Viefleur [7K]

Answer:

48 times 14

Step-by-step explanation:

5 0

3 years ago

Can you help me please i do. not get this

xenn [34]

Answer:

5 13/24

Step-by-step explanation:

(10 5/12) - (4 7/8) = (10 +5/12) -(4 +7/8)

... = (10 -4) +(5/12 -7/8)

... = 6 + (5/12 -7/8) . . . . . read on for how to simplify this

_____

Adding fractions

Adding fractions can be done in a mechanical sort of way using the formula ...

... a/b + c/d = (ad +bc)/(bd)

Here, we have a=5, b=12, c=-7, d=8, so the sum is ...

... (5·8 +12(-7))/(12·8) = (40 -84)/96 = -44/96

The numerator and denoinator of this fraction are both multiples of 4, so we can reduce the fraction.

... -44/96 = 4(-11)/(4·24) = -11/24

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Back to the problem at hand

... 6 + (5/12 -7/8) = 6 - 11/24

Now, we know that 1 = 24/24, so when we subtract 11/24 from 1, we get ...

... 1 - 11/24 = 24/24 - 11/24 = (24 -11)/24 = 13/24

So, our expression 6 - 11/24 can be rewritten as ...

... 6 -11/24 = (5 + 1) - 11/24 = 5 + (1 -11/24) = 5 13/24

Summary

... (10 5/12) - (4 7/8) = 5 13/24

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Another way to add fractions

The way to add fractions that is commonly taught is to first find a common denominator. Here that means you want to find the smallest number that is a multiple of both 12 and 8, the two denominators. You may recognize that number as being 24 = 12·2 = 3·8. (The methods of finding the common denominator (least common multiple) for numbers not in your memorized multiplication tables are not easy to describe.)

The next step in this method is to rewrite the fractions so they each have this denominator. The multipliers in the above equation are helpful for that purpose.

... 5/12 = (5·2)/(12·2) = 10/24

... 7/8 = (7·3)/(8·3) = 21/24

Now, the subtraction can proceed easilly:

... 10/24 - 21/24 = (10 -21)/24 = -11/24 . . . . . same result as above

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4 years ago

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Verdich [7]

Answer:

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Step-by-step explanation:

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4 years ago

Please help 100 points.​

Please help 100 points.