In Hamilton County, Ohio the mean number of days needed to sell a house is 86 days (Cincinnati Multiple Listing Service, April, 2012). Data for the sale of 40 houses in a nearby county showed a sample mean of 80 days with a sample standard deviation of 20 days. Conduct a hypothesis test to determine whether the mean number of days until a house is sold is different than the Hamilton county mean of 86 days in the nearby county. Round your answer to four decimal places. p-value = ?
Use a = .05 for the level of significance, and state your conclusion.