During the summer months, wildfires in the western United States pose a great hazard to people, residential and commercial buildings, and animals. Previous records indicate that the mean number of...

During the summer months, wildfires in the western United States pose a great hazard to people, residential and commercial buildings, and animals. Previous records indicate that the mean number of acres burned during a wildfire is 17,060. The most recent summer was unusually wet, and firefighting officials would like to know whether the mean number of acres burned during wildfires was any less. State the null and alternative hypotheses.

Tourism officials in Palm Beach County, Florida, claim that the mean diameter of sand dollars found on Delray Beach is 4.25 centimeters. Some scientists claim that warmer water off the coast has inhibited growth of all sea life and that the diameter of sand dollars has decreased. State the null and alternative hypothesis.

The stereotypical video-game player is a male teenager. However, recent studies suggest that at least 45% of all players are women.4 A software company has decided to develop and market a sophisticated stock-market video game if the mean age of all video-game players is greater than 25. A random sample of players will be obtained, and the resulting data will be used to test the relevant hypothesis. Let m represent the mean age of all video-game players. Which of the following sets of null and alternative hypotheses is appropriate? Justify your answer.