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3 years ago

Please explain how to do please

Mathematics

1 answer:

patriot [66]3 years ago

7 0

You have to find out what ?x7=21 and 7 because you need to include 1 for the other fish so ?=3 but then you have to multiply 3x6 and it equals 18 so then 18-3.I hope this was helpful.Btw the answer is 15 letter C.

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George is building a fence around a rectangular dog run. He is using his house as one side of the run. The area of the dog run w

pav-90 [236]

Answer:

width is 30-22 = 8 feet

George would need 76 feet of fencing for the dog run

Step-by-step explanation:

30 x (30-x) = 240

30-x = 8

-x = -22

x = 22

Therefore width is 30-22 = 8 feet

8+8+30+30 = 76

Thus, George would need 76 feet of fencing for the dog run

8 0

2 years ago

Pls help i am on a timer

salantis [7]

Answer: (x-6)(x+1)

Step-by-step explanation:

Sum : x2 − 5 x- 6

x2 + x-=6 x − 6

factor pair: x 2 + x − 6 x − 6

x( x+ 1 ) − 6 ( x + 1 )

rewrite from: x (x + 1 ) − 6 ( x + 1 )

(x-6)(x+1)

8 0

3 years ago

Read 2 more answers

2.21586210 rounded to four decimal places

Vadim26 [7]

Answer:

Sorry I really don't know :(

Step-by-step explanation:

Very sorry

7 0

3 years ago

In parallelogram ABCD , diagonals AC¯¯¯¯¯ and BD¯¯¯¯¯ intersect at point E, BE=2x2−3x , and DE=x2+10 .

Basile [38]

There is an answer for this question http://web2.0calc.com/questions/in-parallelogram-abcd-diagonals-ac-and-bd-intersect

5 0

3 years ago

Read 2 more answers

The head librarian at the Library of Congress has asked her assistant for an interval estimate of the mean number of books check

Verdich [7]

Answer:

$n=(\frac{1.960(150)}{90})^2 =10.67 \approx 11$

So the answer for this case would be n=11 rounded up to the nearest integer

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$\bar X$ represent the sample mean for the sample

$\mu$ population mean (variable of interest)

$\sigma =150$ represent the population standard deviation

n represent the sample size

Solution to the problem

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

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

The confidence interval for this case is given by: (740, 920)

We can find the estimate for the mean and we got:

$\bar X = \frac{740+920}{2} = 830$

and the margin of error is given by :

$ME = \frac{920-740}{2}= 90$

The margin of error is given by this formula:

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

And on this case we have that ME =90 and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=(\frac{z_{\alpha/2} s}{ME})^2$ (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:

$n=(\frac{1.960(150)}{90})^2 =10.67 \approx 11$

So the answer for this case would be n=11 rounded up to the nearest integer

5 0

3 years ago