Question

The report "Digital Democracy Surveyt describes a large national survey. In a representative sample of Americans ages 14 to 18 years, 45% indicated that they usually use social media while watching

TV. Suppose that the sample size was 760.
(a) Is there convincing evidence that less than half of Americans ages 14 to 18 years usually use social media while watching TV? Use a significance level of 0.05.
State the appropriate null and alternative hypotheses.
O Hop 0.5 versus Hp > 0.5
O Moip 0.5 versus H: = 0.5
O Hp = 0.5 versus HP < 0.5
OH:P < 0.5 versus , p > 0.5
OHOD 0.5 versus H: 0.5
Find the test statistic and P-value. (Use a table or technology. Round your test statistic to two decimal places and your p-value to four decimal places.)
ZE
P-value

Answer 1

H0 : p = 0.5 versus H1: P < 0.5

Test statistic = - 2.76

Pvalue = 0.0029

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.