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3 years ago

In the figure, if CD = 15 cm, then BC ≈ cm.

Mathematics

2 answers:

laiz [17]3 years ago

6 0

The answer is the last option which is 34.7 cm. I did the test so I know this is correct

Alona [7]3 years ago

3 0

Check the picture below.

make sure your calculator is in Degree mode, since the angles are in degrees.

You might be interested in

What’s the inverse function for f(x) 6x-5

MAXImum [283]

Answer:

g(x)= (1/6)x+5/6 is the inverse function of f(x)

Step-by-step explanation:

We have y= 6x-5

Then, we take x depending on y like:

6x-5=y

6x-5 +5 = y + 5

6x= y+5

6x/6=y/6 + 5/6

x= y/6+ 5/6

Now, we replace x by the function g(x) and y by the variable x, then we have

g(x)= (1/6)x+5/6 is the inverse function of f(x).

Hope that you understand.

6 0

2 years ago

1. What would the polynomial x + 7 – 4x^3 be written as in standard form?

yarga [219]

Hello there!

The only thing we need to do to get this polynomial in standard form is rearrange the terms!

x+7-4x^3
-4x^3+x+7 is the polynomial written in standard form. Remember to keep track of the negatives!

The GCF of the polynomial
24x^5+18x^9 is...
6x^5
Because it is the greatest term that goes into both 24x^5 AND 18x^9!
This will end up helping you factor later on.
6x^5(4+3x^4)

I really hope this helps!
Best wishes :)

5 0

3 years ago

Mary ravi and Alan have a total of $62 in their wallets. Mary has $6 more than Ravi. Alan has 2 times what Mary has. How much do

mixas84 [53]

Answer:

Marry = $17

Ravi = $11

Alan = $34

Step-by-step explanation:

Let us assume

Mary be X

Ravi be Y

Alan be Z

So, the equation in total is

X + Y + Z = 62

It is given that

X = Y + 6

Z = 2X

Now we put the Z value in the total equation, so it would be

X + Y + 2X = 62

3X + Y = 62 .................................... (1)

And can we write

X = Y + 6

X - Y = 6 ................................. (2)

Now substitution these two equations,

3X + Y = 62

X - Y = 6

2X = 68

X = $17

So, Z = 2 × 17 = $34

And, Y

$17 + Y + $34 = $62

So, Y = $11

5 0

2 years ago

Type the correct answer in each box.

Vitek1552 [10]

Answer:

The coordinates of the point that is a reflection of Y(-4, -2) across the x-axis are ( -4,2).

The coordinates of the point that is a reflection of Y across the y-axis are ( 4,-2).

Step-by-step explanation:

Reflection across x-axis

The rule used for Reflection across x-axis is that y-coordinate becomes negated while x coordinate remains same.

So,

The coordinates of the point that is a reflection of Y(-4, -2) across the x-axis are ( -4,2).

Because according to definition, x-coordinate remains same, while y-coordinate is negated. So x-coordinate = -4, y-coordinate = 2

Reflection across y-axis

The rule used for Reflection across y-axis is that x-coordinate becomes negated while y coordinate remains same.

So,

The coordinates of the point that is a reflection of Y across the y-axis are ( 4,-2).

Because according to definition, y-coordinate remains same, while x-coordinate is negated. So x-coordinate = 4, y-coordinate = -2

7 0

3 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