Question 1055827
F(x)=exp^(-3)*3^x/x!
For x=0, P(x)=exp^(-3)=0.0498
For x=3, exp (-3)*27/6=0.2240
for x> 1
prob x=1 is exp^(-3)*3=0.1494
Prob x>1 is 1-(0.0498+0.1494)=0.8008
The z value is (x-mean)/sd
With sd of 0.24 sec, it is 2.5 sds to the left of the mean (-z) and +1.6667 sd to the right of the mean (positive)
The probability that z is between those two values of -2.5 and 1.6667 is 0.9460.