The following data were collected in an experiment designed to investigate the impact of different positions of the mother during ultrasound on fetal heart rate.Fetal heart rate is measured by ultrasound in beats per minute.The study includes 20 women who are assigned to one position and have the fetal heart rate measured in that position.Each woman is between 28-32 weeks gestation.The data are shown below.

Back Side Sitting Standing

140 141 144 147

144 143 145 145

146 145 147 148

141 144 148 149

139 136 144 145

Mean = 142.0 Mean = 141.8 Mean = 145.6 Mean =146.8

Is there a significant difference in mean fetal heart rates by position?Run the test at a 5% level of significance.