計(jì)算題: 原子熒光法測定地表水中硒,6次測定值分別為5.1ug/L,5.1ug/L、5.3ug/L、5.3ug/l、5.4ug/L、5.6ug/L,計(jì)算6次測定的相對(duì)標(biāo)準(zhǔn)偏差。