statistics

Past records suggest that the mean annual income, , of teachers in state of Illinois is less than or equal to the mean annual income, , of teachers in Massachusetts. In a current study, a random sample of teachers from Illinois and an independent random sample of teachers from Massachusetts have been asked to report their mean annual income. The data obtained are as follows:

	Annual income in dollars
Illinois	40798, 49829, 55580, 38200, 52863, 41809, 54541, 43947, 46246, 47331, 37087, 56376, 57860, 37832, 56347, 45117, 37371, 53131, 42055, 47494
Massachusetts	31716, 52735, 43011, 49275, 47499, 44999, 48098, 33943, 31841, 38314, 45029, 42095, 47204, 44940, 43467, 44481, 37140, 40926, 52063, 47472