1. A cereal manufacturer seeks to test their newest product against a competitor's. A group of 100 children was asked to evaluate each brand, and then to express a preference. To guard against bias, neither the children, nor the technicians serving them, were aware of the order in which they were fed each brand.
I. What is the population?
II. What is the sample?
III. Is the study observational or experimental? Justify your answer.
IV. If observational, identify ALL variables. If experimental, identify ALL independent and dependent variables.
V. For each of the variables identified in part IV, list which of the four levels/scales of measurement was used to obtain data on these variables?
VI. Classify each of the variables identified in part IV as either attribute or numerical.
2. Classify the following variable as nominal, ordinal, discrete, or continuous and state why it is such a variable:
3. Classify the following as an example of a nominal, ordinal, interval, or ratio level of measurement, and state why it represents this level:
Ages of patients in a physician's office
4. Construct a frequency distribution table to organize the following set of data:
21.5 21.6 21.2 21.5 21.6 22.0 22.0 21.1 21.4 21.4
21.8 21.5 21.6 21.3 21.8 21.9 21.9 21.1 21.5 21.3
5. Construct a grouped frequency distribution for the following 28 scores using a class width of 4:
83 85 78 95 74 86 84 94 97 81 74 93 76 80
94 88 95 76 82 94 77 88 91 88 91 87 84 84
6. Provide a different example for each of the following types of variables from your work or home life:
A) A continuous variable
B) An ordinal level of measurement
The expert examines populations and samples. The study observational and experimental are defined.