British Petroleum has recently been investing in oil fields in the former Soviet Union.4 Before deciding whether to buy an oilfield, the company wants to estimate the number of barrels of oil that the oilfield can supply. For a given well, the company is interested in a purchase if it can determine that the well will produce, on average, at least 1,500 barrels a day. A random sample of 30 days gives a sample mean of 1,482 and the population standard deviation is 430. Construct a 95% confidence interval. What should be the company's decision?