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 Ha.
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. |

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