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3 years ago

6

Let m = 2x+5and P= 7x-1 find 3x^2(M-P)

1 answer:

Makovka662 [10]3 years ago

4 0

Answer:

Step-by-step explanation:

The way you solve this equation is by substituting in the values we know:

3 $x^{2}$ [(2x + 5) - (7x-1)]

Then you have to simplify:

3 $x^{2}$ (-5x + 6)

And then you multiply:

-15 $x^3$ + 18 $x^{2}$

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Suppose that you were not given the sample mean and sample standard deviation and instead you were given a list of data for the

Troyanec [42]

Answer:

So, the sample mean is 31.3.

So, the sample standard deviation is 6.98.

Step-by-step explanation:

We have a list of data for the speeds (in miles per hour) of the 20 vehicles. So, N=20.

We calculate the sample mean :

$\mu=\frac{19 +19 +22 +24 +25 +27 +28+ 37 +35 +30+ 37+ 36+ 39+ 40+ 43+ 30+ 31+ 36+ 33+ 35}{20}\\\\\mu=\frac{626}{20}\\\\\mu=31.3$

So, the sample mean is 31.3.

We use the formula for a sample standard deviation:

$\sigma=\sqrt{\frac{1}{N-1}\sum_{i=1}^{N}(x_i-\mu)^2}$

Now, we calculate the sum

$\sum_{i=1}^{20}(x_i-31.3)^2=(19-31.3)^2+(19-31.3)^2+(22-31.3)^2+(24-31.3)^2+(25-31.3)^2+(27-31.3)^2+(28-31.3)^2+(37-31.3)^2+(35-31.3)^2+(30-31.3)^2+(37-31.3)^2+(36-31.3)^2+(39-31.3)^2+(40-31.3)^2+(43-31.3)^2+(30-31.3)^2+(31-31.3)^2+(36-31.3)^2+(33-31.3)^2+(35-31.3)^2\\\\\sum_{i=1}^{20}(x_i-31.3})^2=926.2\\$

Therefore, we get

$\sigma=\sqrt{\frac{1}{N-1}\sum_{i=1}^{N}(x_i-\mu)^2}\\\\\sigma=\sqrt{\frac{1}{19}\cdot926.2}\\\\\sigma=6.98$

So, the sample standard deviation is 6.98.

3 0

3 years ago

If it is assumed that the heights of men are normally distributed with a standard deviation of 2.5 inches, how large a sample sh

Volgvan

Answer:

30 men

Step-by-step explanation:

In order to be sure that the sample mean does differ from the population mean by more than 0.90, the sample size (n) that should be used is given by:

$0.90 < Z\frac{s}{\sqrt{n}}$

Where 'Z' , for a 95% probability is 1.960, 's' is the standard deviation of 2.5 inches:

$0.90 > 1.960\frac{2.5}{\sqrt{n}}\\n >(\frac{1.960*2.5}{0.9})^2\\n>29.64$

Rounding up to the nearest whole number, the sample size should be at least 30 men.

7 0

3 years ago

Number 2 how do I do it I really do not know how to do it

irga5000 [103]

Um Mabry ask for help or reread

8 0

4 years ago

Read 2 more answers

Simplify the expression 5 + 2 ×[(2+2)×5+5]

Ivan

5 + 2 * [(2 + 2)*5+5] =

5 + 2 * (4 * 5 + 5) =

5 + 2 * 25 =

5 + 50=

55

8 0

4 years ago

The graph represents the cost y (in dollars) to open an online gaming account and buy x games. Write an equation in slope-interc

Luba_88 [7]

Answer:

y = 10x + 15

Step-by-step explanation:

you pick two points on the line

I picked (3,45) and (6,75)

you subtract the two x’s and y’s

75 - 45 = 30 (30 is the rise) you go up from 45 to 75

6 - 3 = 3 (you move 3 times to the right to get to the 6) so 3 is the run

slope = rise/run so 30/3 = 10

The y-intercept is the place you start on the graph so that is 15

8 0

3 years ago

Read 2 more answers