A National Trend Predicts That Women Will Account for Half

Short Answer

A national trend predicts that women will account for half of all business travelers in the next three years. To attract these women business travelers, hotels are providing more amenities that women particularly like. A recent survey of American hotels found that 70% offer hairdryers in the bathrooms. Consider a random and independent sample of 20 hotels. Find the probability that at least 9 of the hotels in the sample do NOT offer hairdryers in the bathrooms.