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Naddika [18.5K]
2 years ago
8

Find the sum 45+46+47+48+...+129+130

Mathematics
1 answer:
Leno4ka [110]2 years ago
6 0
Use photo math to help you with this question
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Answer:

my answer is X=3/2 or 1.5

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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.

b)

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.

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2 years ago
Select the statement that describes the expression 7+2n
sineoko [7]

c

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2n is multiplication

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The second Version of the game is greater for hitting the down button because substituting any number for x, the second equation would always end up having a greater amount.
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A large number of randomized experiments were conducted to determine whether taking a particular drug regularly would decrease t
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Step-by-step explanation:

b

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