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3 years ago

What’s this question

Mathematics

1 answer:

shusha [124]3 years ago

8 0

Multiply the first equation by -1

-3x-y=-4

2x+y=5

Add them up

-x=1

So x=-1

And y=7

So the first option is correct

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Solve this: -4a = -52

Greeley [361]

Answer:

Hello! answer: 13

Step-by-step explanation:

-4 × 13 = 52 therefore a = 13 HOPE THAT HELPS!

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3 years ago

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Which equation requires the multiplication property of equality to be solved?

prohojiy [21]

Answer:

201.6 = 11.2f

Step-by-step explanation:

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Mortgage rates: Following are interest rates (annual percentage rates) for a 30-year fixed rate mortgage from a sample of lender

andreev551 [17]

Answer:

98% Confidence interval: (4.144 ,4.498)

Step-by-step explanation:

We are given the following in the question:

4.751, 4.373, 4.177, 4.676, 4.425, 4.228, 4.125, 4.251, 3.951, 4.192, 4.291, 4.414

Formula:

$\text{Standard Deviation} = \sqrt{\displaystyle\frac{\sum (x_i -\bar{x})^2}{n-1}}$

where $x_i$ are data points, $\bar{x}$ is the mean and n is the number of observations.

$Mean = \displaystyle\frac{\text{Sum of all observations}}{\text{Total number of observation}}$

$Mean =\displaystyle\frac{51.854}{12} = 4.321$

Sum of squares of differences = 0.5602

$s = \sqrt{\dfrac{0.5602}{11}} = 0.226$

98% Confidence interval:

$\bar{x} \pm t_{critical}\displaystyle\frac{s}{\sqrt{n}}$

Putting the values, we get,

$t_{critical}\text{ at degree of freedom 11 and}~\alpha_{0.02} = \pm 2.718$

$4.321 \pm 2.718(\frac{0.226}{\sqrt{12}} ) = 4.321 \pm 0.1773 = (4.144 ,4.498)$

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4 years ago

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4. The mean of the distribution of compy heights is 33.5 cm, and the standard deviation is 2.56 cm. Interpret the mean and stand

alina1380 [7]

Answer:

a) The average of compy heights is 33.5 cm

b) The 68.3 % of all compy heights are in the interval:

(30.94,36.06)

Step-by-step explanation:

a) Meaning of the mean

The mean is a number expressing the central or typical value in a set of data.

The average of compy heights is 33.5 cm. If the select one height randomly its height will be in average 33.5 cm

b) Meaning of standard deviation

The standard deviation is a quantity expressing by how much the members of a group differ from the mean value for the group.

The 68.3 % of all compy heights are in the interval

(33.5cm - 2.56cm, 33.5cm + 2.56cm) = (30.94,36.06)

It means that the 68.3 % of all data is in the interval:

(μ - δ, μ +δ)

Where: μ is the mean

δ is the standard deviation

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3 years ago

Lambert High School is planning on building a new indoor batting practice building. The length of the building on the blueprint

Yakvenalex [24]

The answer is 50 ft.

20 x 2.5 = 50 ft

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