Catheters During an angiogram, heart problems can be examined via a small tube (a catheter) threaded into the heart from a vein in the patients leg. Its important that the company that manufactures the catheter maintain a diameter of 2.00 mm. (The standard deviation is quite small.) Each day, quality control personnel make several measurements to test H0: m = 2.00 against HA: m _ 2.00 at a significance level of a = 0.05. If they discover a problem, they will stop the manufacturing process until it is corrected. a) Is this a one-sided or two-sided test? In the context of the problem, why do you think this is important? b) Explain in this context what happens if the quality control people commit a Type I error. c) Explain in this context what happens if the quality control people commit a Type II error.

Statistics 260 1/22/18 – 1/26/18 Chapter 2 Why do we have statistics - The census is taken every 10 years by law - Due to technology we can take estimates during years in which we can’t take the actual census - Pulling data from the population o We are able to discover true parameters o It takes a lot of time and money to count the entire population so we can take a sample instead o We use a sample to find statistics do estimate parameters. Costs less time and money - Two branches o Descriptive statistics Numerical summaries of graphical displays of data. Graphical Numerical DESCRIPING data