xs10n
幼苗
共回答了25个问题采纳率:92% 举报
.
x 甲 =
1
8 (12.1+12.2+13+12.5+13.1+12.5+12.4+12.2)=12.5,
.
x 乙 =
1
8 (12+12.4+12.8+13+12.2+12.8+12.3+12.5)=12.5,
s 甲 2 =
1
8 [(12.1-12.5 ) 2 +(12.2-12.5 ) 2 +(13-12.5 ) 2 +(12.5-12.5 ) 2 +(13.1-12.5) 2 +(12.5-12.5) 2 +(12.4-12.5) 2 +(12.2-12.5) 2 ]=0.12,
s 乙 2 =
1
8 [(12-12.5 ) 2 +(12.4-12.5 ) 2 +(12.8-12.5 ) 2 +(13-12.5 ) 2 +(12.2-12.5) 2 +(12.8-12.5) 2 +(12.3-12.5) 2 +(12.5-12.5) 2 ]=0.10,
因为两名选手的平均数相同,所以方差小的选手发挥更稳定.
故答案为:乙选手参赛更好,因为
.
x 甲 =
.
x 乙 =12,5 , s 甲 2 =0.12 , s 乙 2 =0.10 ,所以乙选手成绩比甲选手成绩稳定,派乙选手参赛更好.
1年前
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