Question 14 (5 points)

Mathematics

1 answer:

kolbaska11 [484]3 years ago

5 0

Answer:A

Step-by-step explanation:

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Which is an irrational number between -9 and -10?

UkoKoshka [18]

Answer:

maybe -9.1666 top second one?

5 0

2 years ago

Read 2 more answers

Consider a population list x with μx=10 and SDx = 1. A second population list, y, with μy=10 and SDy=2, is added to the first li

Basile [38]

Answer:

The combined standard deviation is 1.58114.

Step-by-step explanation:

The formula to compute the combined standard deviations of two different data sets is:

$SD_{c} =\sqrt{\frac{n_{X}S^{2}_{X}+n_{2}S^{2}_{Y}+n_{X}(\mu_{X}-\mu_{c})^{2}+n_{Y}(\mu_{Y}-\mu_{c})^{2}}{n_{X}+n_{Y}}$

Here $\mu_{c}$ is the combined mean given by:

$\mu_{c}=\frac{n_{X}\mu_{X}+n_{Y}\mu_{Y}}{n_{X}+n_{Y}}$

It is provided that the sample size is same for both the data sets, i.e. $n_{X} = n_{Y}=n$

Compute the combined mean as follows:

$\mu_{c}=\frac{n_{X}\mu_{X}+n_{Y}\mu_{Y}}{n_{X}+n_{Y}}\\=\frac{(n\times10)+(n\times10)}{n+n}}\\=\frac{20n}{2n}\\ =10$

Compute the combined standard deviation as follows:

$SD_{c} =\sqrt{\frac{n_{X}S^{2}_{X}+n_{2}S^{2}_{Y}+n_{X}(\mu_{X}-\mu_{c})^{2}+n_{Y}(\mu_{Y}-\mu_{c})^{2}}{n_{X}+n_{Y}}}\\=\sqrt{\frac{(n\times1^{2})+(n\times2^{2})+(n(10-10))+(n(10-10))}{n+n}}\\=\sqrt{\frac{n+4n}{2n} } \\=\sqrt{\frac{5n}{2n} } \\=\sqrt{\frac{5}{2}} \\=1.58114$

Thus, the combined standard deviation is 1.58114.

3 0

3 years ago

Which ordered pair (a, b) is the solution to the following system of equations?

Kamila [148]

Answer:

(-13, -4)

Step-by-step explanation:

It is about as easy to try the solutions as it is to find them from scratch.

However, we can determine which one it is by adding twice the second equation to the first.

(-2a +3b) +2(a -4b) = (14) +2(3)

-5b = 20

b = -4 . . . . . . matches the first choice

8 0

3 years ago

insens350 [35]

To start, the equation has to be converted to slope-intercept form, or $y=mx+b$ . Start by subtracting x from both sides; $x-x+2y=4$ , $2y=4-x$ . Switch 4 and -x around to conform to the formula; $2y=-x+4$ . Then divide by 2 to isolate y; $y=-\frac{1}{2}x+2$ . This is the final equation. Because the slope of a line perpendicular is always the opposite reciprocal (i.e. The opposite reciprocal of 4 is $-\frac{1}{4}$ , the opposite reciprocal of $-\frac{1}{5}$ is 5) the opposite reciprocal of $-\frac{1}{2}$ is 2. So the equation of the line is $y=2x$ , and the answer is A.