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xxTIMURxx [149]
3 years ago
13

Perchlorate is a chemical used in rocket fuel. People who live near a former rocket-testing site are concerned that perchlorate

is present in unsafe amounts in their drinking water. Drinking water is considered safe when the average level of perchlorate is 24.5 parts per billion (ppb) or less. A random sample of 28 water sources in this area produces a mean perchlorate measure of 25.3 ppb. Which of the following is an appropriate alternative hypothesis that addresses their concern?
A) H: 25.3.
B) H: > 25.3.
C) H u <24.5.
D) Hu> 24.5. 27.
Mathematics
1 answer:
ser-zykov [4K]3 years ago
8 0

Answer:

H_1 : \mu  > 24.5

Step-by-step explanation:

From the given information:

The sample size is 28

The population mean is 24.5 (ppb)

The sample mean is 225.3 (ppb)

Thus, the null and the alternative hypothesis can be computed as:

Null hypothesis:

H_o : \mu \le 24.5

Alternative hypothesis:

H_1 : \mu  > 24.5

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Montano1993 [528]
Circumference is equal to diameter multiplied by pi. C=d X pi. To find the radius we need to rearrange this equation. We know what pi and the circumference are, so to find diameter we do circumference divided by pi. D=c/pi. 942/pi = 299.85. This gives us the diameter, for the radius simply divide by 2 which is 149.92 :)
5 0
3 years ago
The diagram below represents the net of a triangular prism. What is the surface area of the triangular prism?
AleksandrR [38]

Answer:

(C)

Step-by-step explanation:

The diagram is divided ninto 5 parts that is rectangles ABCD, CHGD, GFEH and  triangles CIH and DGJ.

Area of rectangle ABCD= l{\times}b

=12{\times}6=72cm^{2}

Area rectangle CDHG=  l{\times}b

=12{\times}8=96cm^{2}

Area rectangle HGFE= l{\times}b

=10{\times}12=120cm^{2}

Area of triangles CIH and DIG= 2{\times}\frac{1}{2}{\times}b{\times}h

=6{\times}8=48cm^{2}

Surface area of the triangular prism=Area of rectangle ABCD+Area rectangle CDHG+Area rectangle HGFE+Area of triangles CIH and DIG

=72+96+120+48=336cm^{2}

Hence, option C is correct.

3 0
3 years ago
Please help &lt;3
Aleksandr [31]

Answer:

x =3

Step-by-step explanation:

3(4x + 4) = 2(5x+9) - 12

First step is to open the brackets by multiplying. It becomes

3×4x + 3×4 = 2×5x + 2×9 -12

12x + 12 = 10x + 18 - 12

Collecting like terms on the right hand side and left hand side of the equation, it becomes

12x -10x = 18 -12 -12

2x = -6

Negative sign on the right hand side of the equation overwhelms the positive sign on left hand side of the equation. It becomes

2x = -6

x = -6/2 = -3

Checking

3(4×-3 + 4) = 2(5×-3+9) - 12

-24 = -12-12= -24

So x = -3

3 0
3 years ago
A textbook company keeps track of its daily cost for printing whole textbooks to different schools, but can only print up to 500
seraphim [82]
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C(100)=3.5*100+1200=1550
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1900=3.5x+1200
3.5x=1900-1200
x=700/3.5= 200
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Part E: C(40.5)=1341.75 I think this statement is incorrect given the context because x means number of books to print so this value must be an integer number.
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3 years ago
3. These 3 congruent square pyramids can be assembled into a cube with side length 1
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Answer:

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Step-by-step explanation:

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3 years ago
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