A recent article describes the success of business schools in Europe and the demand on that continent for the MBA degree. The article reports that a survey of 280 European business positions resulted in the conclusion that only one-seventh of the positions for MBAs at European businesses are currently ?lled. Assuming that these numbers are exact and that the sample was randomly chosen from the entire population of interest, give a 90% con?dence interval for the proportion of ?lled MBA positions in Europe.