A statewide real estate agency, New Colony, specializes in residential home sales in southern California. Records indicate the mean selling time of homes is 90 days. Because of recent water concerns, the agency believes that the mean selling time may have increased. A regional survey of 100 homes sold recently revealed that the mean selling time was 94 days with a standard deviation of 22 days. At a .1 significance level, can we conclude that the mean selling time has increased?