hi everyone...
I just encountered a problem...quite strange.....It is the first time that I am wondering the answer is wrong actually.
The problem is :
A fair die is tossed until the first 5 appears. Let X denotes the random variable equal to the number of tosses required.
Compute E[14X].
seems quite easy at first...I thought this is a geometric distribution
and E(14x) = 14E(x) then E(x) = 6. woo...then the answer comes out...
but the right answer is 119.....completely lost
Plz help...A million thanks!!!!
I just encountered a problem...quite strange.....It is the first time that I am wondering the answer is wrong actually.
The problem is :
A fair die is tossed until the first 5 appears. Let X denotes the random variable equal to the number of tosses required.
Compute E[14X].
seems quite easy at first...I thought this is a geometric distribution
and E(14x) = 14E(x) then E(x) = 6. woo...then the answer comes out...
but the right answer is 119.....completely lost
Plz help...A million thanks!!!!
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