Statistics

Question

In a study of homicide on the job, University of North Carolina researchers collected data on workplaces where an employee was murdered. (American Journal of Epidemiology, Vol. 154, 2001.) In a sample of 105 cases, 67 of the homicides occurred during night hours (between 9 P.M. and 6 A.M.). a.Give a point estimate of p, the true proportion of on-the-job homicide cases that occurred at night. b.Compute a 95% confidence interval for p. c.Give a practical interpretation of the interval, part b.

Answer

Farrah,<BR><BR>a. The point estimate is just 67/105 = 0.638.<BR>b. A 95% confidence interval would be p +/- 2*sqrt(npq)/n = (0.544,0.732).<BR>c. Based on the available information, we can say that we have 95% certainty that the true proportion of&nbsp;<BR>homicides on the job is between 0.544 and 0.732.&nbsp;&nbsp;<BR><BR>Hope this helps,<BR><BR>Joe http://vrd.askvrd.org/services/answerschema.xml