Practice Problem 1 Your instructor claims 50% of the beads in a container are red. A random sample of 251 beads is selected, of which 107 are red. Calculate and interpret a 90% confidence interval for the proportion of red beads in the container. Use your interval to comment on this claim. Practice Problem 2 The Nielson Company is a global information and media company and one of the leading suppliers of media information. In their state-of-the-media report, they announced that U.S. cell phone subscribers average 5.4 hours per month watching videos on their phones. Does this average seem reasonable? We draw the following SRS of size 12 from this population: 11.9, 2.8, 3.0, 6.2, 4.7, 9.8, 11.1, 7.8, 4.0, 5.5, 7.1, 10.2 Practice Problem 3 A manufacturer of high-resolution video terminals must control the tension on the mesh of fine wires that lies behind the surface of the viewing screen. The tension is measured by an electrical device with output readings in millivolts. A random sample of 20 screens has the following mean and standard deviation: = 306.32 = 36.21. Assuming the data are approximately normal, estimate the true mean tension of all the video terminals produced this day