A first step towards identifying spam is to create a list of words that are more likely to appear in spam than in normal messages. Suppose a specified list of words is available and that your data base of 5000 messages contains 1500 that are spam. Among the spam messages, 1286 contain words in the list. Of the 3500 normal messages, only 247 contain words in the list. What is the probability that a message is spam given that the message contains words in the list.