According to the local union president, the mean gross income of plumbers is normally distributed, with a mean of $60000 and a standard deviation of $6000. An investigative reporter for the local television station recently found, for a sample of 120 plumbers, the mean gross income was $62500. At the 0.10 significance level, is it reasonable to conclude that the mean income is not equal to $60 000? Determine the p-value and the 90% confidence interval. Use this information to support your decision.