I need help with this question please​

Using the z-distribution, as we are working with a proportion, it is found that the 95% confidence interval for the difference in the proportions of teenagers with access to smartphones in 2017 and in 2013 is of (0.393, 0.507).

In 2017, 450 out of 600 students had access, hence:

[tex]p_1 = \frac{450}{600} = 0.75, s_1 = \sqrt{\frac{0.75(0.25)}{600}} = 0.0177[/tex]

In 2013, 120 out of 400 students had access, hence:

[tex]p_2 = \frac{120}{400} = 0.3, s_2 = \sqrt{\frac{0.3(0.7)}{400}} = 0.0229[/tex]

For the distribution of differences, we have that the mean and the standard error are, respectively, given by:

[tex]p = p_1 - p_2 = 0.75 - 0.3 = 0.45[/tex]

[tex]s = \sqrt{s_1^2 + s_2^2} = \sqrt{0.0177^2 + 0.0229^2} = 0.0289[/tex]

It is given by:

[tex]p \pm zs[/tex]

95% confidence level, hence[tex]\alpha = 0.95[/tex], z is the value of Z that has a p-value of [tex]\frac{1+0.95}{2} = 0.975[/tex], so [tex]z = 1.96[/tex].

Then:

[tex]p - zs = 0.45 - 1.96(0.0289) = 0.393[/tex]

[tex]p + zs = 0.45 + 1.96(0.0289) = 0.507[/tex]

The 95% confidence interval for the difference in the proportions of teenagers with access to smartphones in 2017 and in 2013 is of (0.393, 0.507).

More can be learned about the z-distribution at https://brainly.com/question/25890103

Answer:

0.45+-0.057

Step-by-step explanation:

Answer:

ans = 9 degree

Step-by-step explanation:

81 + (4x) + (5x+18) = 180 (The sum of all angles of triangle is 180 degree)

81 + 4x + 5x + 18 = 180

99 + 9x = 180

9x = 180 - 99

9x = 81

x = [tex]\frac{81}{9}[/tex]

x = 9 degree

Answer:

B. 7

Step-by-step explanation:

To find this out, first, we multiply 89*2, which is 178, the amount already spent on toner.

Then, we add 27 to this to find the total amount spent so far. This comes out to $205 spent so far.

To find out how much we have left to spend, we subtract the amount spent from the original.

400-205 = $195, the amount of money left.

To find out how much paper we can buy, we divide the cost of one paper box, by the amount of money we have left.

195/27 = 7.222222222222222222222222222222

Since we cannot buy 7.222222222222222222222222 boxes, we can only buy 7. This is the answer.

Answer:

Step-by-step explanation:he equation for circumference is:

c=2%28pi%29r

The equation for area is:

a=%28pi%29r%5E2

First, we'll find the circumference.

The 'r' in the equation stands for radius. The radius of a circle is half of its diameter, so the circle's radius is half of 6--3 inches.

So, we can substitute 3 in for 'r' and 3.14 in for pi

c=2%28pi%29r

c=2%2A3.14%2A3

Then, we can simply multiply.

c=2%2A3.14%2A3

c=18.84

Therefore, the circumference of the circle is 18.84

Next, we'll find the circle's area.

Again, we can substitute 3 in for 'r' and 3.14 in for pi

a=%28pi%29r%5E2

a=3.14%2A3%5E2

The, we'll square three and multiply.

a=3.14%2A3%5E2

a=3.14%2A9

a=28.26

Therefore, the circumference is 18.84 and the area is 28.26.

Answer:

No 1.5 is greater than 0.88

Step-by-step explanation:

Your Welcome please Mark Brainliest

- Nathaniel Cross

Answer:

Slope is 60/1 or simply 60. Miles per hours is also 60

Step-by-step explanation:Rise/Run Up60 Over1 which is why slope =60, mph is same as slope or just calculate how many miles car goes in one hour by reading the graph.

The interior angles of any triangle sum to 180° in measure, and in ∆ABC, the angles at vertices A and C are congruent. If we call their measure a, then

24° + 2a = 180°   ⇒   2a = 156°   ⇒   a = 78°

The angle at vertex C and the angle with measure (2x - 18)° are supplementary, meaning they add up to 180° :

a + (2x - 18)° = 180°

Solve for x :

78° + (2x - 18)° = 180°

(2x - 18)° = 102°

2x = 120

x = 60

hope it's helpful at you all

Answer:

Let's simplify step-by-step. 5n2−4n+6+4n2−2n−3

=9n2−6n+3

Answer:

The answer to that is 371200ft2

Step-by-step explanation:

725 x 512 = 371200ft2

Answer:

the answer is 40 7\10

Step-by-step explanation:

7 2\5 x 5 1\2= 407\10 = 40 7\10

Answer:

15000

Step-by-step explanation:

150x100

15000

Answer:

4 and -3

Step-by-step explanation:

2x+6=0

2x=-6

-3

x-4=0

x=4

So its 4 and -3

Answer:

-3,4

Step-by-step explanation:

(2x+6)(x-4) = 0

Using the Zero Factor Principle: If ab =0 then a=0 or b=0

2x+6=0 or X-4=0

solve 2x+6=0:

2x+6=0

Subtract 6 from both sides

2x+6-6 0-6

Simplify

2x = -6

Divide both sides by 2

2x/2 = -6/2

Simplify

X=-3

then x-4 =0

add 4 from to both sides

x=4

zeros : -3,4

(-3,0),(4,0)

Answer:

c

Step-by-step explanation:

lucky guess

Answer:

x = 80.34 (2 dp)

Step-by-step explanation:

[tex]2\ln(x)+7=\ln(4x)+10[/tex]

[tex]\implies \ln(x^2)+7=\ln(4x)+10[/tex]

[tex]\implies \ln(x^2)-\ln(4x)=10-7[/tex]

[tex]\implies \ln\left(\dfrac{x^2}{4x}\right)=3[/tex]

[tex]\implies \ln\left(\dfrac{x}{4}\right)=3[/tex]

[tex]\implies e^{\ln\left(\dfrac{x}{4}\right)}=e^3[/tex]

[tex]\implies \dfrac{x}{4}=e^3[/tex]

[tex]\implies x=4e^3[/tex]

[tex]\implies x=80.34 \textsf{ (2 dp)}[/tex]

Answer:

x = 1

explanation:

[tex]\sf \rightarrow \dfrac{3}{x} -1 = 2[/tex]

[tex]\sf \rightarrow \dfrac{3}{x} = 2+1[/tex]

[tex]\sf \rightarrow \dfrac{3}{x} = 3[/tex]

[tex]\sf \rightarrow {3} = 3(x)[/tex]

[tex]\sf \rightarrow \dfrac{3}{3} = (x)[/tex]

[tex]\sf \rightarrow x = 1[/tex]

checking if x = 1,

[tex]\sf \rightarrow \dfrac{3}{1} -1 = 2[/tex]

[tex]\sf \rightarrow3 -1 = 2[/tex]

[tex]\sf \rightarrow 2 = 2[/tex]

→ Hence proved x : 1 as L.H.S = R.H.S

Step-by-step explanation:

[tex] \frac{3}{x} - 1 = 2 \\ [/tex]

[tex] \frac{3}{x} - 1 + 1 = 2 + 1 \\ \frac{3}{x} = 3[/tex]

[tex]3 \times x = 3 \times 1 \\ 3x = 3[/tex]

Dividing both sides by 3, we get

[tex] \frac{3x}{3} = \frac{3}{3} \\ x = 1[/tex]

Step-by-step explanation:

let aztecs = x

since the phantoms won 8 more than the aztecs

then, the phantoms = x + 8

and their combined win was 32

therefore

x + x + 8 = 32

2x + 8 =32

2x = 32 - 8

2x = 24 , x = 12

so , aztecs won 12 games and the phantoms won 20 games.

If this helped pls give brainliest

Answer:

1:2

Step-by-step explanation:

18:36

Simplify:

36÷2=1, making 2 a good 2nd term

There are 2 candy bars every 1 lollipop.

1:2

1:2 is the ratio of lollipops to candy bars.

The relationship in quantity, amount, or size between two or more things.

Given that there are 18 lollipops and 36 candy bars,

Ratio = 18/36 = 1/2

Hence, 1:2 is the ratio of lollipops to candy bars.

For more references on Ratio, click;

https://brainly.com/question/13419413

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Answer:

i think the answer is C

Step-by-step explanation:

i normally just do length divided by width to figure this out

Answer:

A Taylor series approximation uses a Taylor series to represent a number as a polynomial that has a very similar value to the number in a neighborhood around a specified x value: f ( x ) = f ( a ) + f ′ ( a ) 1 ! ( x − a ) + f ′ ′ ( a ) 2 !

Step-by-step explanation:

Answer:

B displays correct solutions for x² +9x +12 = 6

step-by-step explanation:

[tex]\rightarrow \sf x^2 + 9x + 12 = 6[/tex]

[tex]\rightarrow \sf x^2 + 9x +12 -6 = 0[/tex]

[tex]\rightarrow \sf x^2 + 9x + 6 =0[/tex]

use the formula:   [tex]\sf \bold{x = \dfrac{ -b \pm \sqrt{b^2 - 4ac}}{2a } \ \ when \ \ \ ax^2 + bx + c = 0}[/tex]

[tex]\rightarrow \sf x = \dfrac{ -9 \pm \sqrt{(-9)^2 - 4(1)(6)}}{2(1)}[/tex]

[tex]\rightarrow \sf x = \dfrac{ -9 \pm \sqrt{57}}{2}[/tex]

[tex]\rightarrow \sf x = \dfrac{ -9}{2} +\dfrac{\sqrt{57}}{2}[/tex]   ;  [tex]\sf x = \dfrac{ -9}{2} -\dfrac{\sqrt{57}}{2}[/tex]

Explanation:

The Law of Cosines can be used to write a quadratic in x. The desired form corresponds to its solution using the quadratic formula.

  [tex]L^2=r^2 +x^2 -2rx\cdot\cos{\theta}\\\\x^2-2rx\cdot\cos{\theta}+(r^2-L^2)=0[/tex]

Using the quadratic formula gives the positive value of x as ...

  [tex]x=\dfrac{-(-2r\cdot\cos{\theta})+\sqrt{(-2r\cdot\cos{\theta})^2-4(1)(r^2-L^2)}}{2(1)}\\\\\boxed{x=r\cos{\theta}+\sqrt{r^2\cos^2\theta+L^2-r^2}}[/tex]

Answer:

n = 9

Step-by-step explanation:

6/8 = n/12

(6/8)(12) = (n/12)(12)

n = 9

Answer:

21

Step-by-step explanation:

First you would subtract 8 from 50 (50 - 8). Once you have that answer, 42, you divide it in half (42/2). Your final answer is 21. The full equation is:

(50 - 8)/2

Answer:

First problem: [tex]y(x)=\frac{1}{2}+e^x-\frac{1}{2}e^{2x}[/tex]

Step-by-step explanation:

Solve for Y(s) by taking the transform of every term

[tex]y''-3y'+2y=1,\:y(0)=1,\:y'(0)=0\\\\\mathcal{L}\{y''\}-3\mathcal{L}\{y'\}+2\mathcal{L}\{y\}=\mathcal{L}\{1\}\\\\s^2Y(s)-sy(0)-y'(0)-3[sY(s)-y(0)]+2Y(s)=\frac{1}{s}\\\\s^2Y(s)-s-3[sY(s)-1]+2Y(s)=\frac{1}{s}\\\\s^2Y(s)-s-3sY(s)+3+2Y(s)=\frac{1}{s}\\\\(s^2-3s+2)Y(s)-s+3=\frac{1}{s}\\\\(s-1)(s-2)Y(s)=\frac{1}{s}-3+s\\\\Y(s)=\frac{1}{s(s-1)(s-2)}-\frac{3+s}{(s-1)(s-2)}[/tex]

Perform partial fraction decomposition

[tex]Y(s)=\frac{1-3s+s^2}{s(s-1)(s-2)}\\\\Y(s)=\frac{s^2-3s+1}{s(s-1)(s-2)}\\ \\\frac{s^2-3s+1}{s(s-1)(s-2)}=\frac{A}{s}+\frac{B}{s-1}+\frac{C}{s-2}\\\\s^2-3s+1=A(s-1)(s-2)+B(s)(s-2)+C(s)(s-1)[/tex]

Solve for each constant

[tex]s^2-3s+1=A(s-1)(s-2)+B(s)(s-2)+C(s)(s-1)\\\\(2)^2-3(2)+1=A(2-1)(2-2)+B(2)(2-2)+C(2)(2-1)\\\\-1=2C\\\\-\frac{1}{2}=C[/tex]

[tex]s^2-3s+1=A(s-1)(s-2)+B(s)(s-2)+C(s)(s-1)\\\\(1)^2-3(1)+1=A(1-1)(1-2)+B(1)(1-2)+C(1)(1-1)\\\\-1=-B\\\\1=B[/tex]

[tex]s^2-3s+1=A(s-1)(s-2)+B(s)(s-2)+C(s)(s-1)\\\\(0)^2-3(0)+1=A(0-1)(0-2)+B(0)(0-2)+C(0)(0-1)\\\\1=2A\\\\\frac{1}{2}=A[/tex]

Take the inverse transform to solve the IVP

[tex]Y(s)=\frac{\frac{1}{2}}{s}+\frac{1}{s-1}+\frac{-\frac{1}{2}}{s-2}\\ \\y(x)=\frac{1}{2}+e^x-\frac{1}{2}e^{2x}[/tex]

Answer:

D. 33

Step-by-step explanation:

Triangle OSP is dilation of 1.5 of triangle NGQ, and side SP corresponds to side GQ.

22*1.5 = 33

Hope this helps :)