Suppose there are 10,000 civilizations broadcasting radio signals in the Milky Way Galaxy right now. Part A On average, how many stars would we have to search before we would expect to hear a signal? Assume there are 500 billion stars in the galaxy. Express your answer using two significant figures. ? NA = stars Submit Request Answer Part B How would the answer change if there were only 130 civilizations instead of 10,000? Express your answer using two significant figures. VO AE NB = stars Submit Request Answer

Suppose there are 10,000 civilizations broadcasting radio signals in the Milky Way Galaxy right now. Part A On average, how many stars would we have to search before we would expect to hear a signal? Assume there are 500 billion stars in the galaxy. Express your answer using two significant figures. ? NA = stars Submit Request Answer Part B How would the answer change if there were only 130 civilizations instead of 10,000? Express your answer using two significant figures. VO AE NB = stars Submit Request Answer