Question

Ê¡Éä»÷¶ÓΪ´Ó¼×¡¢ÒÒÁ½ÃûÔ˶¯Ô±ÖÐÑ¡°ÎÒ»È˲μÓÈ«¹ú±ÈÈü£¬¶ÔËûÃǽøÐÐÁËÁù´Î²âÊÔ£¬²âÊԳɼ¨ÈçÏÂ±í£¨µ¥Î»£º»·£©£º

	µÚÒ»´Î	µÚ¶þ´Î	µÚÈý´Î	µÚËÄ´Î	µÚÎå´Î	µÚÁù´Î
¼×	10	8	9	8	10	9
ÒÒ	10	7	10	10	9	8

£¨1£©¸ù¾Ý±í¸ñÖеÄÊý¾Ý£¬¼ÆËã³ö¼×µÄƽ¾ù³É¼¨ÊÇ

9

»·£¬ÒÒµÄƽ¾ù³É¼¨ÊÇ

9

»·£»
£¨2£©·Ö±ð¼ÆËã¼×¡¢ÒÒÁù´Î²âÊԳɼ¨µÄ·½²î£»
£¨3£©¸ù¾Ý£¨1£©¡¢£¨2£©¼ÆËãµÄ½á¹û£¬ÄãÈÏΪÍƼöË­²Î¼ÓÈ«¹ú±ÈÈü¸üºÏÊÊ£¬Çë˵Ã÷ÀíÓÉ£®
{¼ÆËã²îµÄƽ·½¹«Ê½£ºS²=

1

n

[x₁-

.

x2

+x₂-

.

x2

+¡­x_n-

.

x2

]}£®

Answer 1

·ÖÎö£º£¨1£©¸ù¾Ýͼ±íµÃ³ö¼×¡¢ÒÒÿ´ÎÊý¾ÝµÃ³öÊý¾Ý×ۺϣ¬ÔÙÇó³öƽ¾ùÊý¼´¿É£»
£¨2£©¸ù¾Ýƽ¾ùÊý£¬ÒÔ¼°·½²î¹«Ê½Çó³ö¼×Òҵķ½²î¼´¿É£»
£¨3£©¸ù¾Ýʵ¼Ê´ÓÎȶ¨ÐÔ·ÖÎöµÃ³ö¼´¿É£®

½â´ð£º½â£º£¨1£©¼×£º£¨10+8+9+8+10+9£©¡Â6=9£¬
ÒÒ£º£¨10+7+10+10+9+8£©¡Â6=9£»

£¨2£©s²_¼×=

1

6

[£¨10-9£©²+£¨8-9£©²+£¨9-9£©²+£¨8-9£©²+£¨10-9£©²+£¨9-9£©²]
=

1

6

£¨1+1+0+1+1+0£©=

2

3

£»
s²_ÒÒ=

1

6

[£¨10-9£©²+£¨7-9£©²+£¨10-9£©²+£¨10-9£©²+£¨9-9£©²+£¨8-9£©²]
=

1

6

£¨1+4+1+1+0+1£©=

4

3

£»

£¨3£©ÍƼö¼×²Î¼ÓÈ«¹ú±ÈÈü¸üºÏÊÊ£¬ÀíÓÉÈçÏ£ºÁ½È˵Äƽ¾ù³É¼¨ÏàµÈ£¬ËµÃ÷ʵÁ¦Ï൱£»µ«¼×µÄÁù´Î²âÊԳɼ¨µÄ·½²î±ÈÒÒС£¬ËµÃ÷¼×·¢»Ó½ÏΪÎȶ¨£¬¹ÊÍƼö¼×²Î¼Ó±ÈÈü¸üºÏÊÊ£®

µãÆÀ£º´ËÌâÖ÷Òª¿¼²éÁËƽ¾ùÊýµÄÇó·¨ÒÔ¼°·½²îµÄÇ󷨣¬ÕýÈ·µÄ¼ÇÒä·½²î¹«Ê½Êǽâ¾öÎÊÌâµÄ¹Ø¼ü£®