In a Nanos Research survey of 1000 Canadian adults about how favourable they were toward the Alberta oil sands project, 30.5% were unfavourable and 16.9% were somewhat unfavourable. Of those who were unfavourable, 72.0% agreed that the oil sands project was bad for the environment, whereas the corresponding percentage for those who were somewhat unfavourable was 53.3%. Construct a 90% confidence interval for the difference between those who were unfavourable and those who were somewhat unfavourable as to whether the oil sands project is bad for the environment.