From: Environmental consciousness and choice of bulb for lighting in a developing country
Group (local knowledge) | Obs. | Mean | Std. err. | Std. dev. | [95% conf. interval] | |
---|---|---|---|---|---|---|
No | 705 | .8468085 | .0135745 | .3604277 | .8201572 | .8734598 |
Yes | 899 | .8843159 | .0106734 | .3200238 | .8633682 | .9052636 |
Combined | 1604 | .8678304 | .0084589 | .3387807 | .8512387 | .8844222 |
Difference |  | − .0375074 | .0170226 |  | − .0708962 | − .0041186 |
diff = mean(0) − mean(1) |  | t = − 2.2034 | ||||
Ho: diff = 0 |  | Degrees of freedom = 1602 | ||||
Ha: diff < 0 | Ha: diff! = 0 | Ha: diff > 0 | ||||
Pr(T < t) = 0.0139 | Pr(|T| > |t|) = 0.0277 | Pr(T > t) = 0.9861 |