シロクマチョコレートを買うと,20個に1個の割合でシロクマのぬいぐるみが当たる.どうしてもシロクマのぬいぐるみがほしいAさんはシロクマチョコレートを50個買ったのに1つも当たらなかった.Aさんはシロクマチョコレート株式会社はうそつきだと断定した.しかし,その推論は正しいか?
チョコレートを買った数 エクセルでの計算式 ひとつもシロクマのぬいぐるみが当たらない確率
20 =BINOMDIST(0,C42,0.05,FALSE) 0.358485922
30 =BINOMDIST(0,C43,0.05,FALSE) 0.214638764
40 =BINOMDIST(0,C44,0.05,FALSE) 0.128512157
50 =BINOMDIST(0,C45,0.05,FALSE) 0.076944975
60 =BINOMDIST(0,C46,0.05,FALSE) 0.046069799
70 =BINOMDIST(0,C47,0.05,FALSE) 0.02758369
80 =BINOMDIST(0,C48,0.05,FALSE) 0.016515374
90 =BINOMDIST(0,C49,0.05,FALSE) 0.009888365
100 =BINOMDIST(0,C50,0.05,FALSE) 0.005920529
チョコレートを買った数 エクセルでの計算式 2個以上シロクマのぬいぐるみが当たる確率
20 =1-BINOMDIST(0,C92,0.05,FALSE)-BINOMDIST(1,C92,0.05,FALSE) 0.264160475
20個チョコレートを買ったときの当たりの数
エクセルでの計算式 確率
0 =BINOMDIST(C96,20,0.05,FALSE) 0.358485922
1 =BINOMDIST(C97,20,0.05,FALSE) 0.377353603
2 =BINOMDIST(C98,20,0.05,FALSE) 0.188676801
3 =BINOMDIST(C99,20,0.05,FALSE) 0.059582148
4 =BINOMDIST(C100,20,0.05,FALSE) 0.013327586
5 =BINOMDIST(C101,20,0.05,FALSE) 0.002244646
6 =BINOMDIST(C102,20,0.05,FALSE) 0.000295348
7 =BINOMDIST(C103,20,0.05,FALSE) 3.10893E-05
8 =BINOMDIST(C104,20,0.05,FALSE) 2.65895E-06
9 =BINOMDIST(C105,20,0.05,FALSE) 1.86593E-07
10 =BINOMDIST(C106,20,0.05,FALSE) 1.08028E-08
11 =BINOMDIST(C107,20,0.05,FALSE) 5.16878E-10
12 =BINOMDIST(C108,20,0.05,FALSE) 2.04031E-11
13 =BINOMDIST(C109,20,0.05,FALSE) 6.60829E-13
14 =BINOMDIST(C110,20,0.05,FALSE) 1.73902E-14
15 =BINOMDIST(C111,20,0.05,FALSE) 3.6611E-16
16 =BINOMDIST(C112,20,0.05,FALSE) 6.02155E-18
17 =BINOMDIST(C113,20,0.05,FALSE) 7.45703E-20
18 =BINOMDIST(C114,20,0.05,FALSE) 6.54125E-22
19 =BINOMDIST(C115,20,0.05,FALSE) 3.62396E-24
20 =BINOMDIST(C116,20,0.05,FALSE) 9.53674E-27
第4回 二項分布・ポアソン分布・正規分布に戻る