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2 years ago

Someone please help !!!!

Mathematics

2 answers:

11Alexandr11 [23.1K]2 years ago

8 0

I believe the answer is A

AnnZ [28]2 years ago

6 0

It is A. when you synthetic divide you end up underneath 2 7 0. the 0 is the remainder. the other makes 2x+7

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PLEASE HELP!! WILL GIVE BRAINLIEST FOR BEST ANSWER!! Please solve #21.

natulia [17]

Your answer would be sliding. hope that helped

5 0

2 years ago

Read 2 more answers

The sum of two numers is 52 . The difference of the two numbers is 38 . What are the two numbers? Write the two numbers separate

Ray Of Light [21]

Let the first number be 'x' and the second number is 'y'

Equation 1: x + y = 52
Equation 2: x - y = 38

Rearranging equation 2 to make either x or y the subject
x = 38 + y

Substituting x = 38 + y into equation 1

x + y = 52
(38+y) + y = 52
38 + 2y = 52
2y = 52 - 38
2y = 14
y = 7

Substitute y = 7 into either equation 1 or equation 2 to find x

x + y = 52
x + 7 = 52
x = 52 - 7
x = 45

x = 45
y = 7

8 0

3 years ago

Could some please help and explain?

Sophie [7]

Answer:

x = 7

Step-by-step explanation:

A rhombus is a parallelogram where all sides are equal. Therefore, as we know two sides are equal to 7x+8 and 9x-6, we can say that

7x+8 = 9x - 6

subtract 7x from both sides to put the variable on one side

2x - 6 = 8

add 6 to both sides to isolate the variable and its coefficient

2x = 14

divide both sides by 2 to isolate x

x = 7

7 0

2 years ago

Question 5 (10 points)

Kamila [148]

You have to subtract 4.35 from 15.60 to see for all the children
3x+4.35 = 15.60

5 0

2 years ago

In a random sample of 80 teenagers, the average number of texts handled in a day is 50. The 96% confidence interval for the mean

Nastasia [14]

Answer:

a) $\bar X =\frac{46+54}{2}=50$

And the margin of error is given by:

$ME= \frac{54-46}{2}= 4$

The confidence level is 0.96 and the significance level is $\alpha=1-0.96=0.04$ and the value of $\alpha/2 =0.02$ and the margin of error is given by:

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

We can calculate the critical value and we got:

$z_{\alpha/2} = 2.05$

And if we solve for the deviation like this:

$\sigma = ME * \frac{\sqrt{n}}{z_{\alpha/2}}$

And replacing we got:

$\sigma =4 *\frac{\sqrt{80}}{2.05} =17.45$

b) $ME=z_{\alpha/2}\frac{\sigma}{\sqrt{n}}=2.05 *\frac{17.45}{\sqrt{160}}=2.828$

And as we can see that the margin of error would be lower than the original value of 4, the margin of error would be reduced by a factor $\sqrt{2}$

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

$\mu$ population mean (variable of interest)

$\sigma$ represent the population standard deviation

n=80 represent the sample size

Solution to the problem

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)

For this case we can calculate the mean like this:

$\bar X =\frac{46+54}{2}=50$

And the margin of error is given by:

$ME= \frac{54-46}{2}= 4$

The confidence level is 0.96 and the significance level is $\alpha=1-0.96=0.04$ and the value of $\alpha/2 =0.02$ and the margin of error is given by:

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

We can calculate the critical value and we got:

$z_{\alpha/2} = 2.05$

And if we solve for the deviation like this:

$\sigma = ME * \frac{\sqrt{n}}{z_{\alpha/2}}$

And replacing we got:

$\sigma =4 *\frac{\sqrt{80}}{2.05} =17.45$

Part b

For this case is the sample size is doubled the margin of error would be:

$ME=z_{\alpha/2}\frac{\sigma}{\sqrt{n}}=2.05 *\frac{17.45}{\sqrt{160}}=2.828$

And as we can see that the margin of error would be lower than the original value of 4, the margin of error would be reduced by a factor $\sqrt{2}$

5 0

2 years ago