A nonprofit consumer organization says that less than 18% of the vehicles the organization rated in a
Question:
A nonprofit consumer organization says that less than 18% of the vehicles the organization rated in a recent year have an overall score of 78 or more.
In a random sample of 90 vehicles the organization rated in a recent year, 20% have an overall score of 78 or more. At α = 0.05, can you support the organization’s claim?
(a) Identify the claim and state H0 and Ha.
(b) Determine whether the hypothesis test is left-tailed, right-tailed, or two-tailed, and whether to use a z-test, a t-test, or a chi-square test. Explain your reasoning.
(c) Choose one of the options.
Option 1: Find the critical value(s), identify the rejection region(s), and find the appropriate standardized test statistic.
Option 2: Find the appropriate standardized test statistic and the P-value.
(d) Decide whether to reject or fail to reject the null hypothesis.
(e) Interpret the decision in the context of the original claim.
Step by Step Answer:
Elementary Statistics Picturing The World
ISBN: 9781292260464
7th Global Edition
Authors: Betsy Farber, Ron Larson