Question

vishal was interested in the relationship between a person’s age and their musical preferences. he called all the numbers listed in his city’s telephone directory, and whenever someone answered and agreed to be surveyed, he asked them for their age and interviewed them about their musical preferences.
once he was done, he analyzed his results and found that younger people prefer pop and hip - hop music while older people prefer jazz and classical music.
what type of statistical study did vishal use?
choose 1 answer:
a sample study
b experiment
c observational study

Explanation:

1. Analyze Option A (Sample study): A sample study involves selecting a subset (sample) from a population. But Vishal called all numbers (tried to reach the whole population or a large part, not just a sample for inference), so A is incorrect.
2. Analyze Option B (Experiment): An experiment requires manipulating variables (e.g., assigning groups to different conditions). Vishal only observed and surveyed, no manipulation, so B is incorrect.
3. Analyze Option C (Observational study): An observational study collects data by observing/ surveying without manipulating variables. Vishal surveyed people about age and music preferences (no manipulation), so this fits.

Answer:

C. Observational study