Final answer:
In a randomized survey, random numbers are used to choose areas to investigate, whereas a systematic survey uses a fixed interval grid. The examples given illustrate cluster and systematic sampling techniques, which are important for valid data collection.
Step-by-step explanation:
The type of survey where areas to be investigated are chosen using a table of random numbers is a randomized survey. Conversely, a systematic survey uses a grid of regularly spaced locations to select where to sample. Therefore, the correct answer is:
- In a randomized survey, areas to be investigated are chosen using a table of random numbers.
- A systematic survey uses a grid of regularly spaced locations to select where to sample.
Considering the provided examples and definitions:
- The manager selecting four departments at random for interviews is using a cluster sampling design.
- Sampling different age groups of players for a soccer team represents stratified sampling.
- Interviewing human resource personnel in different companies can be an example of cluster sampling.
- Asking every tenth customer for a survey at a health club is an example of systematic sampling.
All these types of sampling are methods used to ensure the validity of the data gathered in a study and are important to understand when conducting research.