Po(X)=(λt)ᵡe^-(λt)/X! µ=σ²=λt=0.13×15=1.95.
a) Po(X=5)=1.95⁵e⁻¹⋅⁹⁵/5!=0.03343.
b) Po(<5)=Po(0)+Po(1)+Po(2)+Po(3)+Po(4)=
0.14227+0.27743+0.27050+0.17582+0.08571=0.95175 approx. (95.18%)
c) Po(≥5)=1-0.95175=0.04825 approx. (4.83%)
d) Po(3≤X≤7)=Po(3)+Po(4)+Po(5)+Po(6)+Po(7)=
0.17582+0.08571+0.03343+0.01086+0.00303=0.30886 approx. (30.89%)
e) µ=1.95, σ=√1.95=1.40 approx.