A group of adults of 200 aged 21 to 50 were selected from those entering Fit Right Health stores in Washington state, and were randomly divided into two groups. One group was given an herb and the othe placebo. After 6 months, the the number of respiratory tract infections in each group were compared. 1< What is the population. 11. What is the sample. 111Is the study experimental or observational.1V What are the variables? V For each of those variables, what level of measurement (nominal, ordinal, interval, or ratio) was used to obtain data from these variables?

The population is the group of random people selected that entered Fit Right Health.

The samples are the herb and the placebo.
The study is experimental because you are testing a herb on the population.
The variables are the population taking the actual herb and those who are not.
This experiment is a ratio

1. A group of 200 adults aged 21 to 50 were selected from those entering Fit Right Health stores in Washington State, and were randomly divided into two groups. One group was given an herb and the other a placebo. After 6 months, the number of respiratory tract infections in each group were compared.

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.

1. The population in this study would be all adults aged 21 to 50 who enter Fit Right Health stores in Washington state.

11. The sample in this study would be the group of 200 adults aged 21 to 50 who were selected from those entering Fit Right Health stores in Washington state and divided into two groups.

111. The study described is experimental because the participants were randomly divided into two groups and one group was given a specific treatment (herb) while the other group was given a placebo.

V. The variables in this study would include:
- Group assignment: Whether the participant was assigned to the herb group or placebo group (nominal level of measurement).
- Respiratory tract infections: The number of respiratory tract infections experienced by each participant after 6 months, which would be a count variable (ratio level of measurement).

For the variable "Group assignment," the level of measurement used is nominal because it categorizes participants into distinct groups without any inherent ordering.

For the variable "Respiratory tract infections," the level of measurement used is ratio because it represents a count of events (infections) with a meaningful zero point (no infections).