One of the issues that need to be considered by real estate investors is the average length of time that a home stays on the market before sold. Usually, if the mean time on the market is less than 45 days, the real estate market is favourable. To test this in a particular area, a random sample of n = 50 homes that sold during the past 12 months was selected.

The mean for this sample was 42 days. It is believed that the population standard deviation is 18 days.

Given a 0.05 level of significance, what conclusion can be reached?