ÌâÄ¿ÄÚÈÝ
13£®Ä³³ÇÊÐÀíÂÛÔ¤²â2020Äêµ½2024ÄêÈË¿Ú×ÜÊýÓëÄê·ÝµÄ¹ØÏµÈçϱíËùʾ| Äê·Ý202x£¨Ä꣩ | 0 | 1 | 2 | 3 | 4 |
| ÈË¿ÚÊý y£¨Ê®Íò£© | 5 | 7 | 8 | 11 | 19 |
£¨¢ò£©¾Ý´Ë¹À¼Æ2025Äê¸Ã³ÇÊÐÈË¿Ú×ÜÊý£®
²Î¿¼ÊýÖµ£º0¡Á5+1¡Á7+2¡Á8+3¡Á11+4¡Á19=132£¬02+12+22+32+42=30£¬
²Î¿¼¹«Ê½£ºÓÃ×îС¶þ³Ë·¨ÇóÏßÐԻع鷽³ÌϵÊý¹«Ê½ $\hat b=\frac{{\sum_{i=1}^n{{x_i}{y_i}-n\overline x\overline y}}}{{\sum_{i=1}^n{x_i^2-n{{\overline x}^2}}}}£¬\hat a=\overline y-\hat b\overline x$£®
·ÖÎö £¨¢ñ£©ÀûÓñíÖÐÊý¾Ý£¬¼ÆËã$\overline{x}$¡¢$\overline{y}$£¬Çó³ö»Ø¹éϵÊý£¬Ð´³ö»Ø¹é·½³Ì£»
£¨¢ò£©°Ñx=5´úÈëÏßÐԻع鷽³ÌÇó³ö$\stackrel{¡Ä}{y}$µÄÖµ¼´¿É£®
½â´ð ½â£º£¨¢ñ£©ÀûÓñíÖÐÊý¾Ý£¬¼ÆËã$\overline{x}$=$\frac{1}{5}$¡Á£¨0+1+2+3+4£©=2£¬
$\overline{y}$=$\frac{1}{5}$¡Á£¨5+7+8+11+19£©=10£¬
¼ÆËã»Ø¹éϵÊý$\hat b=\frac{{\sum_{i=1}^n{{x_i}{y_i}-n\overline x\overline y}}}{{\sum_{i=1}^n{x_i^2-n{{\overline x}^2}}}}$
=$\frac{0¡Á5+1¡Á7+¡+4¡Á19-5¡Á2¡Á10}{{0}^{2}{+1}^{2}+¡{+4}^{2}-5{¡Á2}^{2}}$
=$\frac{132-100}{30-20}$
=3.2£¬¡£¨3·Ö£©
$\stackrel{¡Ä}{a}$=$\overline{y}$-$\stackrel{¡Ä}{b}$$\overline{x}$=10-3.2¡Á2=3.6£¬¡£¨6·Ö£©
¹ÊÏßÐԻع鷽³ÌΪ$\stackrel{¡Ä}{y}$=3.2x+3.6£» ¡£¨8·Ö£©
£¨¢ò£©¸ù¾Ý£¨¢ñ£©µÄ½á¹û£¬°Ñx=5´úÈëÏßÐԻع鷽³Ì$\stackrel{¡Ä}{y}$=3.2x+3.6£¬
¼ÆËã$\stackrel{¡Ä}{y}$=3.2¡Á5+3.6=19.6£»
ËùÒÔÔ¤²â2005Äê¸Ã³ÇÊÐÈË¿Ú×ÜÊýΪ196Íò£® ¡£¨12·Ö£©
µãÆÀ ±¾Ì⿼²éÁËÏßÐԻع鷽³ÌµÄÇó·¨ÓëÓ¦ÓÃÎÊÌ⣬ÊÇ»ù´¡Ì⣮
| A£® | £¨-6£¬1£© | B£® | £¨-6£¬1] | C£® | £¨1£¬2£© | D£® | [1£¬2£© |
| A£® | f¡ä£¨x0£©=0 | B£® | f¡å£¨x0£©£¾0 | ||
| C£® | f¡ä£¨x0£©=0ÇÒf¡å£¨x0£©£¾0 | D£® | f¡ä£¨x0£©=0»òf¡ä£¨x0£©²»´æÔÚ |
| A£® | yƽ¾ù¼õÉÙ2.5¸öµ¥Î» | B£® | yƽ¾ù¼õÉÙ0.5¸öµ¥Î» | ||
| C£® | yƽ¾ùÔö¼Ó2.5¸öµ¥Î» | D£® | yƽ¾ùÔö¼Ó0.5¸öµ¥Î» |