Question

The mean happiness score on the measure of happiness was 25 and the standard deviation was zero. This shows that

Answer 1

The mean happiness score on the measure of happiness was 25 and the standard deviation was zero. This shows that

all sample people having same, identical happiness score i.e 25.

example : suppose three score 24,25,26  

mean = 25 but standard deviation is 1.

Take another three score 25,25,25

mean = 25 but standard deviation is zero.

Conclusion: The mean happiness score on the measure of happiness was 25 and the standard deviation was zero. This shows that all happiness score are equal i.e. 25