Question

2. Home Heating

A housing survey of single-family homes in two provinces is conducted to determine the proportion of such homes that have gas heat. A sample of 300 homes in Province A shows 185 have gas heat, compare with 75 of 200 in Province B. Compare the proportions of single-family homes with gas heat.

To study the effectiveness of wall insulation in saving energy for home heating, the energy consumption (in MWh) for 10 houses was recorded for two winters – one before insulation and one after. Test whether insulation has reduced average energy consumption.

House: 1 2 3 4 5 6 7 8 9 10

Before: 12.1 11.0 14.1 13.8 15.5 12.2 12.8 9.9 10.8 12.7

After: 12.0 10.6 13.4 11.2 15.3 13.6 12.6 8.8 9.6 12.4

Answer 1