﹙4.4+4.7+4.5+4.6+4.8+4.6+4.5+4.7﹚÷8÷10=0.46﹙米／步﹚﹙38+40+39+42+41﹚÷5=40﹙步﹚40×0.46=18.4﹙米﹚55.2÷0.46=120﹙步﹚
