関連ワード:  when do we use step deviation method    when do we use step deviation method in statistics    when should we use step deviation method    when do we use step deviation mean method    when we use step deviation method to find mean    can we use step deviation method    when do we use assumed mean method and step deviation method    can we use step deviation method in boards    do we have step deviation method    when do we use direct method assumed mean method and step deviation method