Roadblock State police set up a roadblock to estimate the percentage of cars with up-to-date registration, insurance, and safety inspection stickers. It would be too inconvenient and costly to check every vehicle that passes through a checkpoint, so they decide to stop about 1/20 of the vehicles. a) Why would a simple random sample be unreasonable for this situation. b) Identify two possible sampling schemes that could be used. Explain how randomization would be used in each.

Statistics 130M Notes January 19, 2017 notes= January 26, 2017 class Tuesday January 24, 2017 Sick- Skipped Class. Sorry All Thursday January 26, 2017 Chapter 3 Numerical descriptive techniques - Allows us to be precise - Most mathematical calculations Information - When interrupting a histogram we focus on shape Population - Described by parameters - Parameters are often written using greek letters Summaries for symmetric distribution - Central tendency o Balancing point/ halfway point o ***should be same**** o Average of mean o Center of symmetric distribution Skewed distribution - Extreme values/ outliers effected the average - Curve killer - Don’t use balancing point Arithmetic mean