1)P(x=k)=[(0.6)^(k-1)]*0.4
2)P=P(2)+P(4)+...+P(10)
=0.24+0.24*0.36+0.24*0.36^2...+0.24*0.36^4
=0.373
P=P(2)+P(4)+...+P(2k)
=0.24+0.24*0.36+0.24*0.36^2...+0.24*0.36^(k-1)
=0.24(1-0.36^k)/(1-0.36)
当k趋于无穷时,0.36^k趋于0
所以P=0.24/0.64=0.375
(1)
x 1 2 3 … k … n
p 0.4 0.24 0.144 … 0.6^(k-1) … 1-0.6^(n-1)
(2)
P(x取偶数)=P(x=2)+P(x=4)+……+P(x=10)
=(约)0.3727
此后P很小,由此估计X取偶数的概率为0.37
另注:实际计算X取偶数的概率
每一个偶数项是前一个奇数项的0.6倍,P=0.6/(1+0.6)=0.375