The number of deaths among the army personnel is 8 in 1000, but among the civilian population it is 20 per 1000. Which one of the following inferences can be drawn from this statement?

Explanation:

The correct answer is D) The groups cannot be compared due to their heterogeneity.

1. Why D is correct: Army personnel are a highly selected group. They are generally young, fit, and healthy individuals who have passed rigorous physical and medical examinations. They also typically have access to good healthcare. The civilian population, on the other hand, is a heterogeneous group, comprising people of all ages (infants, elderly), varying health conditions (sick, disabled), and diverse lifestyles. Comparing a death rate from a pre-selected, generally healthy, younger population (army) with that of an unselected, diverse population (civilians) is misleading because the inherent differences in the composition of the groups (their heterogeneity) make a direct comparison invalid.

2. Why A is incorrect: "It is better to join the army" is a subjective judgment and an oversimplification. A lower death rate alone does not define "better" without considering the context, risks, and overall life experience. More importantly, it ignores the fundamental differences in the demographic profiles of the two groups.

3. Why B is incorrect: "The relationship is fortuitous" means accidental or by chance. The observed difference in death rates is unlikely to be purely by chance. It is systematically influenced by factors like age distribution, health screening, access to medical care, and occupational risks inherent to each group.

4. Why C is incorrect: "Quality of Life Index is very high within the armed forces" cannot be directly inferred from a death rate alone. While the armed forces might offer certain benefits and healthcare, a lower death rate primarily reflects the younger, healthier demographic of the army, rather than being a comprehensive measure of Quality of Life, which encompasses many other factors. The heterogeneity of the groups remains the primary reason for the difference in death rates.