The simplified equation after clearing the decimals is
-12.2 + 2.8w - 8.8 = 1.05w

-21=-4w

w=5.25

but you don’t want decimals

so- you round down

w=5

Step-by-step explanation:

You combine like terms, and then make sure your variable is alone, the only way to get it alone from a ”mixed number”  is to divide

you do the same thing to both sides

so divde each side by -4

-21/-4 = 5.25

or with it rounded down since it’s under a five

It’s 5 with the decimals removed

i hope this helps

H0 : p = 0.5 versus H1: P < 0.5

Test statistic = - 2.76

Pvalue = 0.0029

Step-by-step explanation:

The hypothesis :

We are to test if less Than half of the American population within the of 14 to 18 years usually use social media while watching TV :

Hence, population proportion, p = 0.5

H0: p = 0.5

H1: P < 0.5

Sample size, n = 760

Sample proportion, Phat = 45% = 0.45

The test statistic, Z :

Z = (Phat - P) / √[(P(1 - P)) /n]

Z = (0.45 - 0.5) / √[(0.5(1 - 0.5)) /760]

Z = - 0.05 / √0.0003289

Z = - 2.7568 ; Z = - 2.76 (2 decimal places)

The Pvalue :

Using technology :

Pvalue from Zscore calculator ; Pvalue = 0.0029

Decision region :

Reject H0 if Pvalue < α

α = 0.05

Since 0.0029 < 0.05 ; we reject the Null and conclude that less than half of American within age 14 to 18 years usually use social media while watching TV.