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?

Kindly check explanation

Step-by-step explanation:

The data table :

Use of SM _UK _China _ Russia _US _ col total

Yes 480 __215 ___343 __640 _ 1678

No 320 _ 285 ___357__ 360 _ 1322

Row Total__ 800 _500 __ 700_ 1000_ 3000

H0 : p1 = p2 = p3 = p4

H1 : p1 ≠ p2 ≠ p3 ≠ p4

Test statistic :

χ² = Σ(observed - Expected)² / Expected

Expected value of each cell = (Row total * column total) / N

N = grand total

Expected Values:

447.467 _279.667 _ 391.533 _ 559.333

352.533 _ 220.333 _ 308.467 _ 440.667

χ²=(2.36536+14.9527+6.01605+11.6337+3.00232 18.9793+7.63611+14.7665) = 79.352

Degree of freedom, df = (row-1)*(column-1) = (2 - 1) * (4 - 1) = 1 * 3 = 3

Using the Pvalue from Chisquare calculator :

Pvalue(79.352, 3) = 0.00000000001

Decision region :

Reject H0 ; If Pvalue < α

α = 0.05

Since 0.000000001 < 0.05 ; Reject H0 and conclude that not all population proportion are equal.

Sample proportion :

Phat = number of yes, x / total

For UK, Phat = 480/800 = 0.6

For China , Phat = 215/500 = 0.43

For Russia , Phat = 343/700 = 0.49

For US, Phat = 640/1000 = 0.64

f(x) has value 150 at x= 0

and 0 at x= 3

so d(f(x))/dt = slope = -150/3 = -50