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3 years ago

Simplify this expression. 20.25 − 912 + 11

Mathematics

2 answers:

iren [92.7K]3 years ago

8 0

20.25-923 person above

AysviL [449]3 years ago

5 0

Answer:

20.25-923

Step-by-step explanation:

20.25-923

912+11=923

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What is the measure of

sergejj [24]

The answer is C 40 degrees

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3 years ago

You have the option of two phone plans. The Link One plan will charge you $0.50 for a phone call, plus $0.40 per minute. The Fam

katrin [286]

.50 + .40m = .48m where m is the number of minutes that equalize the cost......subtract .40m from each side

.50 = .08m divide both sides by .08

.50 /.08 = m = 6.25 minutes

8 0

4 years ago

Please help me I’m so lost !!!!

Tasya [4]

Answer:

$4095$

Step-by-step explanation:

$\sum _{n=1}^63\left(4^{n-1}\right)\:$

$\sum _{n=1}^63\cdot \:4^{n-1}$

Compute general progression:

$\frac{3\cdot \:4^{\left(n+1\right)-1}}{3\cdot \:4^{n-1}}=4$

$r=4\\$

$a_1=3\cdot \:4^{1-1}$

$a_1=3$

nth term is computed by:

$r=4,\:a_n=3\cdot \:4^{n-1}$

plug in the values $n=6,\:\spacea_1=3,\:\spacer=4$ :

$=3\cdot \frac{1-4^6}{1-4}$

$=4095$

5 0

4 years ago

The y-intercept of the line whose equation is 2x + y = 4 is -2 2 4

Ber [7]

The y intercept is the value of y when x=0. Substituting we get

y = 4

Answer: 4

8 0

3 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