ÌâÄ¿ÄÚÈÝ
11£®2015Äê2ÔÂ27ÈÕ£¬ÖÐÑëÈ«ÃæÉ¸Ä¸ïС×éÉóÒéͨ¹ýÁË¡¶Öйú×ãÇò¸Ä¸ï×ÜÌå·½°¸¡·£¬Öйú×ãÇòµÄáÈÆðÖ¸ÈÕ¿É´ý£¡ÒÑÖªÓмס¢ÒÒ¡¢±ûÈýÖ§×ãÇò¶Ó£¬Ã¿Á½Ö§Çò¶ÓÒª½øÐÐÒ»³¡±ÈÈü£¬±ÈÈüÖ®¼äÏ໥¶ÀÁ¢£®£¨1£©Èô¼×¡¢ÒÒ¡¢±ûÈýÖ§×ãÇò¶ÓʵÁ¦Ï൱£¬Ã¿Á½Ö§Çò¶Ó±ÈÈüʱ£¬Ê¤¡¢Æ½¡¢¸ºµÄ¸ÅÂʾùΪ$\frac{1}{3}$£¬
Çó¼×¶ÓÄܱ£³Ö²»°ÜµÄ¸ÅÂÊ
£¨2£©Èô¼×¡¢ÒÒÁ½¶ÓʵÁ¦Ï൱£¬ÇÒÓÅÓÚ±û£¬¾ßÌåÊý¾ÝÈçϱí
Èô»ñʤһ³¡»ý3·Ö£¬Æ½Ò»³¡»ý1·Ö£¬ÊäÒ»³¡»ý0·Ö£¬¼ÇX±íʾ¼×¶ÓµÄ»ý·Ö£¬ÇóXµÄ·Ö²¼ÁкÍÊýѧÆÚÍû
¸ÅÂÊ Ê¼þ | ¼×ʤÒÒ | ¼×ƽÒÒ | ¼×ÊäÒÒ |
¸ÅÂÊ | $\frac{1}{3}$ | $\frac{1}{3}$ | $\frac{1}{3}$ |
¸ÅÂÊ Ê¼þ | ¼×ʤ±û | ¼×ƽ±û | ¼×Êä±û |
¸ÅÂÊ | $\frac{2}{3}$ | $\frac{1}{6}$ | $\frac{1}{6}$ |
¸ÅÂÊ Ê¼þ | ÒÒʤ±û | ÒÒƽ±û | ÒÒÊä±û |
¸ÅÂÊ | $\frac{2}{3}$ | $\frac{1}{6}$ | $\frac{1}{6}$ |
·ÖÎö £¨1£©¼×¶ÓÄܱ£³Ö²»°Ü£¬ÓÉÖ¸¼×ºÍÒÒ¡¢±ûÁ½¶Ó±ÈÈüʱ¶¼Ã»ÓÐʧ°Ü£¬ÓÉ´ËÄÜÇó³ö¼×¶Ó±£³Ö²»°ÜµÄ¸ÅÂÊ£®
£¨2£©ÓÉÒÑÖªµÃXµÄ¿ÉÄÜȡֵΪ0£¬1£¬2£¬3£¬4£¬6£¬·Ö±ðÇó³öÏàÓ¦µÄ¸ÅÂÊ£¬ÓÉ´ËÄÜÇó³öXµÄ·Ö²¼ÁкÍE£¨X£©£®
½â´ð ½â£º£¨1£©ÉèʼþAΪ¡°¼×¶ÓÄܱ£³Ö²»°Ü¡±£¬
ÓÉÒÑÖªµÃP£¨A£©=$\frac{2}{3}¡Á\frac{2}{3}$=$\frac{4}{9}$£¬
¼´¼×¶Ó±£³Ö²»°ÜµÄ¸ÅÂÊΪ$\frac{4}{9}$£®¡£¨4·Ö£©
£¨2£©ÓÉÒÑÖªµÃXµÄ¿ÉÄÜȡֵΪ0£¬1£¬2£¬3£¬4£¬6£¬
P£¨X=0£©=$\frac{1}{3}¡Á\frac{1}{6}=\frac{1}{18}$£¬
P£¨X=1£©=$\frac{1}{3}¡Á\frac{1}{6}+\frac{1}{3}¡Á\frac{1}{6}$=$\frac{1}{9}$£¬
P£¨X=2£©=$\frac{1}{3}¡Á\frac{1}{6}$=$\frac{1}{18}$£¬
P£¨X=3£©=$\frac{1}{3}¡Á\frac{1}{6}+\frac{1}{3}¡Á\frac{2}{3}$=$\frac{5}{18}$£¬
P£¨X=4£©=$\frac{1}{3}¡Á\frac{1}{6}+\frac{1}{3}¡Á\frac{2}{3}$=$\frac{5}{18}$£¬
P£¨X=6£©=$\frac{1}{3}¡Á\frac{2}{3}$=$\frac{2}{9}$£¬
¡àXµÄ·Ö²¼ÁÐΪ
X | 0 | 1 | 2 | 3 | 4 | 6 |
P | $\frac{1}{18}$ | $\frac{1}{9}$ | $\frac{1}{18}$ | $\frac{5}{18}$ | $\frac{5}{18}$ | $\frac{2}{9}$ |
µãÆÀ ±¾Ì⿼²é¸ÅÂʵÄÇ󷨣¬¿¼²éÀëÉ¢ÐÍËæ»ú±äÁ¿µÄ·Ö²¼ÁкÍÊýѧÆÚÍûµÄÇ󷨣¬ÊÇÖеµÌ⣬½âÌâʱҪÈÏÕæÉóÌ⣬ÔÚÀúÄê¸ß¿¼Öж¼ÊDZؿ¼ÌâÐÍ£®