有10个人戒烟前和戒烟后五周的体重记录如下

2个回答

  • (1)戒烟前:

    .

    x

    =

    1

    10

    (67+80+69+52+52+60+55+54+64+60)=61.3kg,

    戒烟后:

    .

    x

    =

    1

    10

    (71+80+68+55+57+62+54+52+67+58)=62.4kg;

    (2)戒烟前:S2=

    1

    10

    [(67-61.3)2+(80-61.3)2+(69-61.3)2+(52-61.3)2+(52-61.3)2+(60-61.3)2+(55-61.3)2+(54-61.3)2+(64-61.3)2+(60-61.3)2]=71.81,

    戒烟后:S2=

    1

    10

    [(71-62.4)2+(80-62.4)2+(68-62.4)2+(55-62.4)2+(57-62.4)2+(62-62.4)2+(54-62.4)2+(52-62.4)2+(67-62.4)2+(58-62.4)2]=71.84;

    (3)戒烟后比戒烟前的平均体重要重,戒烟后的体重波动比戒烟前的波动大.体重增加,体质增强.劝吸烟者戒烟,说明吸烟有害健康.