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2 years ago

6+7 (12-5^2) equals?

Mathematics

2 answers:

pickupchik [31]2 years ago

8 0

-85 is the answer (calculator)

Nadya [2.5K]2 years ago

6 0

The correct answer is -85.

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7^2 + 3[81 – (4x6)] please help me!!!!!!!!

Anastaziya [24]

Answer:220

Step-by-step explanation:Simplify

4 0

3 years ago

Find the value of x.

eduard

Answer:

$4/12=x/18$

$x=4*18/12$

$x=6$

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hope it helps...

have a great day!!

6 0

3 years ago

¿Cuál es la fracción equivalente para el número decimal repetitivo 0.33 ...?

Makovka662 [10]

Answer:

33/100

Step-by-step explanation:

0.33------> 33/100

Round the 3 and you get 33 so the decimal is located in the hundreths.

5 0

2 years ago

Assume that the helium porosity of coal samples taken from any particular seam is Normally distributed with true standard deviat

riadik2000 [5.3K]

Answer:

a) $4.85-2.33\frac{0.75}{\sqrt{20}}=4.46$

$4.85+2.33\frac{0.75}{\sqrt{20}}=5.24$

b) $4.56-2.33\frac{0.75}{\sqrt{16}}=4.12$

$4.56+2.33\frac{0.75}{\sqrt{16}}=4.99$

c) $n=(\frac{1.960(0.75)}{0.2})^2 =54.02 \approx 55$

Step-by-step explanation:

Part a

The confidence interval for the mean is given by the following formula:

$\bar X \pm z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (1)

The Confidence is 0.98 or 98%, the value of $\alpha=0.02$ and $\alpha/2 =0.01$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-NORM.INV(0.01,0,1)".And we see that $z_{\alpha/2}=2.33$

Now we have everything in order to replace into formula (1):

$4.85-2.33\frac{0.75}{\sqrt{20}}=4.46$

$4.85+2.33\frac{0.75}{\sqrt{20}}=5.24$

Part b

$4.56-2.33\frac{0.75}{\sqrt{16}}=4.12$

$4.56+2.33\frac{0.75}{\sqrt{16}}=4.99$

Part c

The margin of error is given by this formula:

$ME=z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (a)

And on this case we have that ME =0.4/2 =0.2 we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=(\frac{z_{\alpha/2} \sigma}{ME})^2$ (b)

The critical value for 95% of confidence interval now can be founded using the normal distribution. And in excel we can use this formla to find it:"=-NORM.INV(0.025;0;1)", and we got $z_{\alpha/2}=1.960$ , replacing into formula (b) we got:

$n=(\frac{1.960(0.75)}{0.2})^2 =54.02 \approx 55$

5 0

3 years ago

Please Help Will Give Points

kodGreya [7K]

Answer:

Step-by-step explanation:

3 0

2 years ago

Read 2 more answers