A researcher claims that more than 30% of U.S. smartphone owners use their phone (shopping, social networking and so on) while watching television. In a random sample of 150 adults, 38% say they use their phone while watching television. At α = 0.05, is there enough evidence to support the researcher’s claim?

a. Verify that np ≥ 5 and nq ≥ 5.

b. Identify the claim and state H₀ and H_a.

c. Identify the level of significance α.

d. Find the critical value z₀ and identify the rejection region.

e. Find the standardized test statistic z. Sketch a graph.

f. Decide whether to reject the null hypothesis.

g. Interpret the decision in the context of the original claim.