Probability Sum in R -
i'm trying run probability codes in r without using dice package. know when there 2 vectors, it's possible use outer command generate matrix calculate sums , values dice rolls. there similar can same thing 5 dice rolls?
i'm working on rolling 5 six-sided dice in r , generating code calculate probability of getting between 15 , 20 sum of rolls.
any suggestions?
you simulation:
set.seed(1020) nn<-1e6 #number simulations #on each simulation, check whether sum of 5 # independently rolled (6-sided) dice less # 2.5 away 17.5--equivalently, # sum between 15 & 20; probability # percentage of time happens, # or equivalently, mean of indicator function > mean(replicate(nn,abs(sum(sample(6,5,t))-17.5)<=2.5)) [1] 0.556971
the actual solution 4332/7776=.5570988, can found (inefficient, cares because 6^5=7776) loop:
tot<-0l (i1 in 1:6){ (i2 in 1:6){ (i3 in 1:6){ (i4 in 1:6){ (i5 in 1:6){ s<-i1+i2+i3+i4+i5 tot<-tot+(s>=15&s<=20) } } } } } > tot/6^5 [1] 0.5570988
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