Question: Arresting shoplifters. Shoplifting in the United States costs retailers about $35 million a day. Despite the seriousness of this problem, the National Association of Shoplifting Prevention (NASP) claims that only 50% of all shoplifting are turned over to police (www.shopliftingprevention.org, 2010). A random sample of 40 U.S. retailers were questioned concerning the disposition of the most recent shoplifters they apprehended. A total of 24 were turned over police. Do these data provide sufficient evidence to contradict the NASP?

a) (5 points) Conduct a hypothesis test to answer the question of interest. Use α =.05.

b) (2 points) Is the sample size large enough to use the inferential procedure of part a)?

c) (2 points) Find the observed significance level (p-value) of the hypothesis test in part a). Interpret the value.

d) (2 points) For what values of α would observed significance level be sufficient to reject the null hypothesis of the test you conducted in part a)?