Nurcombe, Howell, Rauh, Teti, Ruoff, and Brennan (1984) conducted an intervention program with mothers of low-birthweight infants (LBW). (It is often difficult to recognize signals from low-birthweight infants, and the program offered training in this domain.) One group of mothers received instruction on responding to subtle signals of LBW infants, while another group did not receive such instruction. A third group of mothers of normalbirthweight infants served as a control group. In addition, mothers were divided by education level. Partial data from that study follow.

(a) Data Group Group 1 Group 2 Group 3 LBW LBW Full Age Education Experimental Control Term Means High School 14 25 18 Education or 20 19 14 Less 22 21 18 13 20 20 13 20 12 18 14 14 13 25 17 14 18 17 Mean 15.875 20.250 16.250 17.485 More Than 11 18 16 High School 11 16 20 Education 16 13 12 12 21 14 12 17 18 13 10 20 17 16 12 13 21 13 Mean 13.125 16.500 15.625 15.083 Group Mean 14.500 18.375 15.938 16.271

(a) Run the appropriate analysis of variance on these results.

(b) What would you conclude about the efficacy of the intervention program?