Table 10.2 Energy consumption of PSH and non PSH
Non-PSH
PSH
Mean (kWh/week)
259.76
200.05
Standard deviation
120.73
56.47
Coefficient of variation
0.46
0.27
Standard error
16.74
9.55
Uncertainty of the mean (90 % confidence interval)
0.11
0.10
Conclusion
The level of precision (Æ10 %) for a 90 %
confidence interval is met for the PSH
group
Fig. 10.2 Fuel mix of the PSH and non PSH groups
180
Y. Franc ¸ois and M. Gavald~ ao