WARMUP A factory has 20 assembly lines producing

WARM-UP A factory has 20 assembly lines producing a popular toy. The company wishes to inspect a representative sample of 100 toys. Through sampling, it finds that 2% of the toys are defective. a. ) Describe each of the sample techniques used : i. ) The control staff randomly selected 5 toys from each Stratified line's output. ii. ) The control staff numbers every toy and uses a random number generator to selected 5 toys. Simple Random Sample (SRS) b. ) What is the Sample? What is the Population? The 100 toys selected All the toys produced c. )What is the population parameter of interest? Proportion of defective toys.

WARM-UP A factory has 20 assembly lines producing a popular toy. The company wishes to inspect a representative sample of 100 toys. Through sampling, it finds that 2% of the toys are defective. d. ) In actuality the entire factory produces 3% defective toys. The 3% represents a: parameter / statistic? While the 2% from the sample represents a: parameter / statistic?

CHAPTER 13 DESIGNING EXPERIMENTS An OBSERVATIONAL STUDY observes individuals and measures variables of interest but does not attempt to influence the response. No Randomness If researchers identify subjects and collected data on their past results this is called a retrospective study. If they use present data as it unfolds this is called a prospective study. An EXPERIMENT deliberately imposes some treatment (specific experimental condition) on individuals in random groups in order to observe their response. (Deliberately Altering the environment).

The individuals on which the experiment is done are the Experimental Units. Humans as E. U. are called Subjects. An experiment is composed of one or more explanatory variables and response variables. The explanatory variables are called FACTORS. There may be many factors in an experiment. Each Factor can have one or more LEVELS. Each Treatment is formed by the combination of the levels of each of the factors. In an experiment with two (2) factors the Number of different treatments = the # of Levels for Factor A times the # of Levels for factor B.

What are the effects of repeated exposure to an advertising message? The answer may depend both on the length of the ad and on how often it is repeated. An experiment investigated this question using undergraduate students as subjects. All subjects viewed a 40 -minutes television program that included ads for a 35 mm camera. Some subjects saw a 30 -second commercial; others, a 90 -second version. The same commercial was repeated either 1, 3, or 5 times during the program. After viewing, all the subjects answered question about their recall of the ad, their attitude toward the camera, and their intention to purchase it. These are the response variables. Each treatment will consist of 12 subjects. 1 time Factor A Length 30 Secs. Treatment 1 90 Secs. Treatment 4 Factor B Repetitions 3 times 5 times Treatment 2 Treatment 3 Treatment 5 Treatment 6 If each treatment combination consisted of 12 students, how many of E. U would you need? 72

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