An automobile association wants to demonstrate that maintaining tire pressure results in better fuel economy. The association selected a random sample of its members, and asked them to record their fuel consumption in litres per 100 km for all of their driving for one month. It then selected another sample of members whose driving habits and car models were the same as the original sample, and asked these drivers to check and adjust tire pressures every 3 to 4 days, for another month, and record their fuel consumption again. Do the data support the association's claim that maintaining tire pressure improves fuel economy? Use α = 0.04.
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