The following data were collected in an experiment designed to investigate the impact of different positions of the mother on fetal heart rate. Fetal heart rate is measured by ultrasound in beats per minute. The study included 20 women who were assigned to one position and had the fetal heart rate measured in that position. Each woman was between 28-32 weeks gestation. The data are shown below.
Back Side Sitting Standing
20 21 24 26
24 23 25 25
26 25 27 28
21 24 28 29
19 16 24 25
Is there a significant difference in mean fetal heart rates by position? Run the test at a 5% level of significance.