If a person smokes a great deal, life length may decrease. This is an example of:

If a person smokes a great deal, life length may decrease. This is an example of:

Options:

(a) negative correlation

(b) investigative sampling

(c) inverse sampling

(d) positive correlation

✅ Correct Option: (a) negative correlation

Explanation (200+ words):

Negative correlation occurs when an increase in one variable leads to a decrease in another. In this example, as smoking increases, life expectancy decreases—demonstrating a negative correlation. Understanding correlation is essential in educational research and statistics. Negative correlation does not imply causation, but it indicates a strong relationship between variables. This concept is frequently tested in PPSC exams under research methods.

10 Related Facts:

Correlation measures relationships. Negative correlation moves in opposite directions. Correlation does not imply causation. Positive correlation moves in same direction. Zero correlation shows no relationship. Pearson’s r measures correlation strength. Research often uses correlational studies. Smoking is linked to health risks. Educational research uses correlation widely. PPSC often tests statistical concepts.