ÌâÄ¿ÄÚÈÝ

3£®Ä³´óѧµÄÒ»¸öÉç»áʵ¼ùµ÷²éС×飬ÔÚ¶Ô´óѧÉúµÄÁ¼ºÃ¡°¹âÅÌÏ°¹ß¡±µÄµ÷–ËÖУ¬Ëæ»ú·¢·ÅÁËl20·ÝÎÊŽ†£®¶ÔÊջصÄl00·ÝÓÐЧÎʾí½øÐÐͳ¼Æ£¬µÃµ½ÈçÏÂ2x2ÁÐÁª±í£º
×ö²»µ½¹âÅÌÄÜ×öµ½¹âÅ̺ϼÆ
ÄÐ451055
Ů301545
ºÏ¼Æ7525100
£¨1£©ÏÖÒÑ°´ÊÇ·ñÄÜ×öµ½¹âÅÌ·Ö²ã´Ó45·ÝÅ®ÉúÎʾíÖгéÈ¡ÁË9·ÝÎÊ¾í£¬Èô´ÓÕâ9·ÝÎʾíÖÐËæ»ú³éÈ¡4·Ý£¬²¢¼ÇÆäÖÐÄÜ×öµ½¹âÅ̵ÄÎʾíµÄ·ÝÊýΪ¦Î£¬ÊÔÇóËæ»ú±äÁ¿¦ÎµÄ·Ö²¼ÁкÍÊýѧÆÚÍû
£¨2£©Èç¹ûÈÏΪÁ¼ºÃ¡°¹âÅÌÏ°¹ß¡±ÓëÐÔ±ðÓйط¸´íÎóµÄ¸ÅÂʲ»³¬¹ýP£¬ÄÇô¸ù¾ÝÁÙ½çÖµ±í×ȷµÄPµÄֵӦΪ¶àÉÙ£¿Çë˵Ã÷ÀíÓÉ£®
¸½£º¶ÀÁ¢ÐÔ¼ìÑéͳ¼ÆÁ¿K2=$\frac{n£¨ad-bc£©^{2}}{£¨a+b£©£¨c+d£©£¨a+c£©£¨b+d£©}$£¬ÆäÖÐn=a+b+c+d£¬
¶ÀÁ¢ÐÔ¼ìÑéÁÙ½ç±í£º
P£¨K2¡Ýk0£©0.250.150.100.050.025
k01.3232.0722.7063.8405.024

·ÖÎö £¨1£©ÒòΪ9·ÝÅ®ÉúÎʾíÊÇÓ÷ֲã³éÑùÈ¡µ½µÄ£¬ËùÒÔÕâ9·ÝÎʾíÖÐÓÐ6·Ý×ö²»µ½¹âÅÌ£¬3·ÝÄÜ×öµ½¹âÅÌ£®ÒòΪ¦Î±íʾ´ÓÕâ9·ÝÎʾíÖÐËæ»ú³éÈ¡µÄ4·ÝÖÐÄÜ×öµ½¹âÅ̵ÄÎʾí·ÝÊý£¬ËùÒÔ¦ÎÓÐ0£¬1£¬2£¬3µÄ¿ÉÄÜÈ¡Öµ£¬Çó³öÏàÓ¦µÄ¸ÅÂÊ£¬¿ÉµÃËæ»ú±äÁ¿¦ÎµÄ·Ö²¼ÁкÍÊýѧÆÚÍû£»
£¨2£©¼ÆËãK2=$\frac{100¡Á£¨45¡Á15-30¡Á10£©^{2}}{55¡Á45¡Á25¡Á75}$¡Ö3.03£¬¿ÉµÃ½áÂÛ£®

½â´ð ½â£º£¨1£©ÒòΪ9·ÝÅ®ÉúÎʾíÊÇÓ÷ֲã³éÑù·½·¨È¡µÃµÄ£¬
ËùÒÔ9·ÝÎʾíÖÐÓÐ6·Ý×ö²»µ½¹âÅÌ£¬3·ÝÄÜ×öµ½¹âÅÌ£®                     ¡­£¨2·Ö£©
ÒòΪ¦Î±íʾ´ÓÕâ9·ÝÎʾíÖÐËæ»ú³é³öµÄ4·ÝÖÐÄÜ×öµ½¹âÅ̵ÄÎʾí·ÝÊý£¬
ËùÒÔ¦ÎÓÐ0£¬1£¬2£¬3µÄ¿ÉÄÜÈ¡Öµ£¬ÓÖ9·ÝÎʾíÖÐÿ·Ý±»È¡µ½µÄ»ú»á¾ùµÈ£¬
ËùÒÔËæ»ú±äÁ¿¦Î·þ´Ó³¬¼¸ºÎ·Ö²¼£¬¿ÉµÃµ½Ëæ»ú±äÁ¿µÄ·Ö²¼ÁÐΪ£º$P£¨¦Î=0£©=\frac{C_6^4}{C_9^4}=\frac{5}{42}$$P£¨¦Î=1£©=\frac{C_6^3C_3^1}{C_9^4}=\frac{10}{21}$$P£¨¦Î=2£©=\frac{C_6^2C_3^2}{C_9^4}=\frac{5}{14}$$P£¨¦Î=3£©=\frac{C_6^1C_3^3}{C_9^4}=\frac{1}{21}$
Ëæ»ú±äÁ¿µÄ·Ö²¼ÁпÉÁбíÈçÏ£º

¦Î0123
P$\frac{5}{42}$$\frac{10}{21}$$\frac{5}{14}$$\frac{1}{21}$
¡­£¨6·Ö£©
ËùÒÔE¦Î=0¡Á$\frac{5}{42}$+1¡Á$\frac{10}{21}$+2¡Á$\frac{5}{14}$+3¡Á$\frac{1}{21}$=$\frac{4}{3}$   ¡­£¨8·Ö£©
£¨2£©K2=$\frac{100¡Á£¨45¡Á15-30¡Á10£©^{2}}{55¡Á45¡Á25¡Á75}$¡Ö3.03¡­£¨10·Ö£©
ÒòΪ2.706£¼3.03£¼3.840£¬
ËùÒÔÄÜÔÚ·¸´íÎóµÄ¸ÅÂʲ»³¬¹ý0.10µÄÇ°ÌáÏÂÈÏΪÁ¼ºÃ¡°¹âÅÌÏ°¹ß¡±ÓëÐÔ±ðÓйأ¬
¼´¾«È·µÄֵӦΪ0.10¡­£¨12·Ö£©

µãÆÀ ±¾Ì⿼²éËæ»ú±äÁ¿¦ÎµÄ·Ö²¼ÁкÍÊýѧÆÚÍû£¬¿¼²é¶ÀÁ¢ÐÔ¼ìÑ飬¿¼²éѧÉú·ÖÎö½â¾öÎÊÌâµÄÄÜÁ¦£¬ÖªÊ¶×ۺϣ®

Á·Ï°²áϵÁдð°¸
Ïà¹ØÌâÄ¿

Î¥·¨ºÍ²»Á¼ÐÅÏ¢¾Ù±¨µç»°£º027-86699610 ¾Ù±¨ÓÊÏ䣺58377363@163.com

¾«Ó¢¼Ò½ÌÍø