Social media is popular around the world. Statista provides estimate of the number of social media users in various countries in as well as the projections for . Assume that the results for surveys in the United Kingdom, China, Russia, and the United States are as follows.

Use Social Media United Kingdom China Russia United States
Yes 480 215 343 640
No 320 285 357 360

Required:
a. Conduct a hypothesis test to determine whether the proportion of adults using social media is equal for all four countries. What is the p-value? Using a .05 level of significance, what is your conclusion?
b. What are the sample proportions for each of the four countries? Which country has the largest proportion of adults using social media?
c. Using a 0.05 level of significance, conduct multiple pairwise comparison tests among the four countries. What is your conclusion?

Answer:

1/512

Step-by-step explanation:

Let staring fraction = x

Half-life = 20 years ; this is the time taken for an element to decrease to half of its original size

Hence,

After 20 years - - - > x/2

After 40 years - - - - > x/2 ÷ 2 = x/2 * 1/2 = x /4

After 60 years - - - - > x/4 ÷ 2 = x/4 * 1/2 = x/8

After 80 years - - - - -> x/8 ÷ 2 = x/8 * 1/2 = x / 16

After 100 years - - - > x/16 * 1/2 = x/32

After 120 years - - - - > x/32 * 1/2 = x/64

After 140 years - - - - -> x / 64 * 1/2 = x / 128

After 160 years - - - - - > x / 128 * 1/2 = x/256

After 180 years - - - - > x/256 * 1/2 = x / 512

Hence, the fraction after 180 years = 1/512

Problem 4a

The instructions are incomplete. You set up the recursive formula, but didn't ask any question about said formula.

I'll assume that your teacher wants you to list out a few terms. I'll list out the first five terms.

The notation a_1 = 4 is the same as writing [tex]a_1 = 4[/tex] where the '1' is a subscript. It tells us that the first term is 4.

The nth term a_n or [tex]a_n[/tex] is defined as such

[tex]a_n = 2*(1/3 + a_{n-1})\\\\[/tex]

Notice how if we replaced n with 2, then we get

[tex]a_n = 2*(1/3 + a_{n-1})\\\\a_2 = 2*(1/3 + a_{2-1})\\\\a_2 = 2*(1/3 + a_1)\\\\[/tex]

So the second term is directly tied to the first term, or it is dependent on it.

We'll replace a_1 with 4 to get the following

[tex]a_2 = 2*(1/3 + a_1)\\\\a_2 = 2*(1/3 + 4)\\\\a_2 = 2*(1/3 + 12/3)\\\\a_2 = 2*(13/3)\\\\a_2 = 26/3\\\\[/tex]

So the second term is 26/3.

As you can guess, the third term is going to be found in a similar fashion

[tex]a_n = 2*(1/3 + a_{n-1})\\\\a_3 = 2*(1/3 + a_{3-1})\\\\a_3 = 2*(1/3 + a_2)\\\\a_3 = 2*(1/3 + 26/3)\\\\a_3 = 2*(27/3)\\\\a_3 = 2*(9)\\\\a_3 = 18\\\\[/tex]

So 18 is the third term.

We'll repeat for n = 4 to get the fourth term.

[tex]a_n = 2*(1/3 + a_{n-1})\\\\a_4 = 2*(1/3 + a_{4-1})\\\\a_4 = 2*(1/3 + a_3)\\\\a_4 = 2*(1/3 + 18)\\\\a_4 = 2*(1/3 + 54/3)\\\\a_4 = 2*(55/3)\\\\a_4 = 110/3\\\\[/tex]

The fourth term is 110/3.

Lastly, we'll plug in n = 5

[tex]a_n = 2*(1/3 + a_{n-1})\\\\a_5 = 2*(1/3 + a_{5-1})\\\\a_5 = 2*(1/3 + a_4)\\\\a_5 = 2*(1/3 + 110/3)\\\\a_5 = 2*(111/3)\\\\a_5 = 2*(37)\\\\a_5 = 74\\\\[/tex]

The fifth term is 74.

==============================================================

Problem 4b

Again, the instructions are missing. I'll assume the same thing as problem 4a.

[tex]a_1 = 6[/tex] is the first term

Plug n = 2 into the first equation to get

[tex]a_n = \frac{n}{a_{n-1}}\\\\a_2 = \frac{2}{a_{2-1}}\\\\a_2 = \frac{2}{a_{1}}\\\\a_2 = \frac{2}{6}\\\\a_2 = \frac{1}{3}\\\\[/tex]

The second term is 1/3.

Repeat for n = 3

[tex]a_n = \frac{n}{a_{n-1}}\\\\a_3 = \frac{3}{a_{3-1}}\\\\a_3 = \frac{3}{a_{2}}\\\\a_3 = \frac{3}{1/3}\\\\a_3 = 3\div\frac{1}{3}\\\\a_3 = 3\times\frac{3}{1}\\\\a_3 = 9\\\\[/tex]

The third term is 9

Repeat for n = 4.

[tex]a_n = \frac{n}{a_{n-1}}\\\\a_4 = \frac{4}{a_{4-1}}\\\\a_4 = \frac{4}{a_{3}}\\\\a_4 = \frac{4}{9}\\\\[/tex]

The fourth term is 4/9

Repeat for n = 5

[tex]a_n = \frac{n}{a_{n-1}}\\\\a_5 = \frac{5}{a_{5-1}}\\\\a_5 = \frac{5}{a_{4}}\\\\a_5 = 5 \div a_{4}\\\\a_5 = 5 \div \frac{4}{9}\\\\a_5 = 5 \times \frac{9}{4}\\\\a_5 = \frac{5}{1} \times \frac{9}{4}\\\\a_5 = \frac{5*9}{1*4}\\\\a_5 = \frac{45}{4}\\\\[/tex]

==============================================================

Problem 4c

I'm not much help here for this problem. Not only are the instructions missing, but it's not clear how this sequence is set up. If I had to guess, it's somehow recursively defined. How exactly, I'm not sure. I would ask your teacher for any clarification.

Answer:

(8.213 ; 8.247)

Step-by-step explanation:

Given the data :

No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Dia. 8.23 8.16 8.23 8.25 8.26 8.23 8.20 8.26 8.19 8.23 8.20 8.28 8.24 8.25 8.24

Sanple size, n = 15

Sample mean, xbar = Σx / n = 123.45 / 15 = 8.23

The sample standard deviation, s = √(x -xbar)²/n-1

Using calculator :

Sample standard deviation, s = 0.03116

s = 0.031 (3 decimal places)

The 95% confidence interval :

C.I = xbar ± (Tcritical * s/√n)

Tcritical at 95%, df = 15 - 1 = 14

Tcritical = 2.145

C.I = 8.23 ± (2.145 * 0.031/√15)

C.I = 8.23 ± 0.0171689

C.I = (8.213 ; 8.247)

Answer:

The slope is -2 and a point on the line is (8,9)

Step-by-step explanation:

The equation is in point slope form

y -y1 = m(x-x1) where (x1,y1) is a point on the line and m is the slope

y-9 = -2(x-8)

The slope is -2 and a point on the line is (8,9)

Answer:

stundeez

Step-by-step explanation:

Nicki Minaj hdhsbskdhsnsk

Answer:

300, 16.67%

Step-by-step explanation:

Let x be the cost price. x-(1/6)x=250. 5x/6=250. x=300. Losss percentage is 16.67%

Answer:

[tex] \dfrac{225}{64} [/tex]

Step-by-step explanation:

[tex] (4^3)^{-2} \times (2^3)^4 \times (\dfrac{8}{15})^{-2} = [/tex]

[tex]= (2^2)^{-6} \times 2^{12} \times (\dfrac{15}{8})^{2}[/tex]

[tex]= 2^{-12} \times 2^{12} \times \dfrac{225}{64}[/tex]

[tex] = \dfrac{225}{64} [/tex]

9514 1404 393

Answer:

  20

Step-by-step explanation:

A whole can be divided into two pieces that are each 1/2 of the whole.

 (10 wholes) × (2 pieces per whole) = 20 pieces

Answer:

A.

Step-by-step explanation:

that is the definition of "mean". it cuts the possible outcomes weighed with their probabilities (actual occurrences vs. possible occurrences) in 2 halves.

The areas are always equal regardless of the mean.

option (a) is correct.

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.

The standard normal distribution is a probability distribution, so the area under the curve between two points tells you the probability of variables taking on a range of values. The total area under the curve is 1 or 100%.

Therefore ,the areas are always equal regardless of the mean.

Learn more details about normal distribution:

https://brainly.com/question/24273691

#SPJ5

Answer:

Resolver para  x

x=8869w/5 - 343

Step-by-step explanation:

simplificando ambos lados de la ecuación, entonces aislar la variable.  x

Step-by-step explanation:

here's the answer to your question

Answer:

31.5

Step-by-step explanation:

Angle Z+ Angle X+ Angle Y=180

As the triangle is isosceles, Z=X, hence Z=63/2=31.5

Answer:

(A)

Step-by-step explanation:

M=-2

therefore

x¹=3, y¹=-12, x²=6 y²=k

M=(y²-y¹)/(x²-x¹)

-2=(k+12)/(6-3)

-2×3=k+12

-6=k+12

k=-18

Answer:

it's hypotenuse

Step-by-step explanation:

[tex]\boxed{ \sf{Answer}} [/tex]

[tex] \sf \: 3(3x - 4) - 5(x + 3) \\ \sf =( 3 \times 3x) - (3 \times 4) + ( - 5 \times x) +( - 5 \times 3 ) \\ \sf = 9x - 12 - 5x - 15 \\ \sf = 9x - 5x - 12 - 15 \\ = \underline{ \bf 4x - 27}[/tex]

ʰᵒᵖᵉ ⁱᵗ ʰᵉˡᵖˢ

꧁❣ ʀᴀɪɴʙᴏᴡˢᵃˡᵗ2²2² ࿐

[tex]\\ \sf\longmapsto 3(3x-4)-5(x+3)[/tex]

[tex]\\ \sf\longmapsto 9x-12-5x-15[/tex]

[tex]\\ \sf\longmapsto 9x-5x-15-12[/tex]

[tex]\\ \sf\longmapsto (9-5)x-27[/tex]

[tex]\\ \sf\longmapsto 4x-27[/tex]

Answer:

the answer of that is number C

Answer:

The p-value of the test is 0.0228, which is less than the standard significance level of 0.05, which means that there is evidence that the proportion of freshmen who graduated in the bottom third of their high school class in 2001 has been reduced.

Step-by-step explanation:

Before solving this question, we need to understand the central limit theorem and subtraction of normal variables.

Central Limit Theorem

The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]

Subtraction between normal variables:

When two normal variables are subtracted, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.

1999:

20 out of 100 in the bottom third, so:

[tex]p_1 = \frac{20}{100} = 0.2[/tex]

[tex]s_1 = \sqrt{\frac{0.2*0.8}{100}} = 0.04[/tex]

2001:

10 out of 100 in the bottom third, so:

[tex]p_2 = \frac{10}{100} = 0.1[/tex]

[tex]s_2 = \sqrt{\frac{0.1*0.9}{100}} = 0.03[/tex]

Test if proportion of freshmen who graduated in the bottom third of their high school class in 2001 has been reduced.

At the null hypothesis, we test if the proportion is still the same, that is, the subtraction of the proportions in 1999 and 2001 is 0, so:

[tex]H_0: p_1 - p_2 = 0[/tex]

At the alternative hypothesis, we test if the proportion has been reduced, that is, the subtraction of the proportion in 1999 by the proportion in 2001 is positive. So:

[tex]H_1: p_1 - p_2 > 0[/tex]

The test statistic is:

[tex]z = \frac{X - \mu}{s}[/tex]

In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, and s is the standard error.

0 is tested at the null hypothesis:

This means that [tex]\mu = 0[/tex]

From the two samples:

[tex]X = p_1 - p_2 = 0.2 - 0.1 = 0.1[/tex]

[tex]s = \sqrt{s_1^2 + s_2^2} = \sqrt{0.04^2 + 0.03^2} = 0.05[/tex]

Value of the test statistic:

[tex]z = \frac{X - \mu}{s}[/tex]

[tex]z = \frac{0.1 - 0}{0.05}[/tex]

[tex]z = 2[/tex]

P-value of the test and decision:

The p-value of the test is the probability of finding a difference of at least 0.1, which is the p-value of z = 2.

Looking at the z-table, the p-value of z = 2 is 0.9772.

1 - 0.9772 = 0.0228.

The p-value of the test is 0.0228, which is less than the standard significance level of 0.05, which means that there is evidence that the proportion of freshmen who graduated in the bottom third of their high school class in 2001 has been reduced.

Answer:

x = 1; y=6

Step-by-step explanation:

y = 2x +4

3x + y = 9

Substitute 2x+4 for y in 3x+y = 9

3x + y = 9

3x + 2x+4 = 9

5x + 4 = 9

5x = 9-4

5x = 5

5x/5 = 5/5

x = 1

Substitute 1 for  x in y = 2x +4

2(1) + 4

2 + 4

= 6

Answered by Gauthmath

Answer:

After 10 months, the loan and value of the car will both be equal to $7,500.

Step-by-step explanation:

Value of the loan after x months:

[tex]y_l = 10000 - 250x[/tex]

Value of the car after x months:

[tex]y_c = 8000 - 50x[/tex]

Which statement describes when Melinda’s loan will be equal to the value of the car?

They are equal when:

[tex]y_l = y_c[/tex]

So

[tex]10000 - 250x = 8000 - 50x[/tex]

[tex]200x = 2000[/tex]

[tex]x = \frac{2000}{200}[/tex]

[tex]x = 10[/tex]

Equal after 10 months:

Value of [tex]y(10) = 8000 - 50(10) = 7500[/tex]

Thus, the correct option is:

After 10 months, the loan and value of the car will both be equal to $7,500.

Step-by-step explanation:

6k + 12 + 9=9

6k + 12 = 9 - 9

6k + 12 = 0

12 = -6k

12/-6 = -6k/-6

2/-1 = k

k = -2

Answer:

k=-2

Step-by-step explanation:

6k+12+9=9

subtract 9 from both sides

6k+12=0

subtract 12 from not sides

6k= -12

divide both sides by 6 (isolating the variable)

k= -12/6

simplify

k= -2

Answer:

b

Step-by-step explanation:

A proportional relationship is a straight line.  Is must also go through the point (0,0)

b

Answer:

Step-by-step explanation:

A proportional relationship is a straight line.  Is must also go through the point (0,0)

Answer:

SR = LK

Step-by-step explanation:

ASA means angle - (included) side - angle.

we got 2 angles confirmed, so all we need is the confirmation of the side between the 2 angles.

Answer:

ask in English then I can help

Step-by-step explanation:

Bro your question is quiet blur... Please help me out..

hope it Wonderful.

^_^....!_!_

Answer:

The answer would be -7x^2 - 14!

Step-by-step explanation:

We can remove the parentheses by distributing the subtraction sign! -2x^2 + x + 1 - x^2 + x - 7 - 4x^2 - 2x - 8. Simplifying this gives us -7x^2 - 14. Hope this helped! :)

Answer:

5 and 6

Step-by-step explanation:

call them a and b, respectively

we have a*b=30 -> a=30/b

a+b=11 -> b+ 30/b=11

b=6 and a=5

1st rectangle:

width: 2.48cm

length: 4.96

2nd rectangle:

width: 4.96 (equals to the length of the 1st rectangle)

area: 9.92

length: 9.92/4.96 = 2

to change unit from feet to cm just divide the length value by 30.48......

Answer:

In a residual plot against x that does NOT suggest we should challenge the assumptions of our regression model, we would expect to see a _____.

c. horizontal band of points centered near 0

Step-by-step explanation:

This residual graph or plot shows the residual values (or the difference between the observed y-value (from scatter plot) and the predicted y-value (from regression equation line) on the vertical axis and displays the independent variable on the horizontal axis.  A linear regression model becomes appropriate for a dataset when the points are randomly dispersed around the horizontal axis near 0; otherwise, a nonlinear model becomes more appropriate.

Answer: guess it your self

Step-by-step explanation: