1. Probability Distribution – Example #2 - homework
Calculate the Mean, Median, Mode, Variance and Standard Deviation of the following probability distribution:

2. Example #2 - Homework X (unsorted) p(X) X (sorted) 7 0.4 2 0.1 4 0.3 8
0.2
Sum
1.0

3. Example #2
Mean = E(X) = Expected Value = (.1) + 4(.3) + 7(.4) + 8(.2) = 5.8;
Median = 7;
Mode = 7 [p(X) = 0.4];
1) E(X2) = 22     0.2 = 37.6;
2) [E(X)]2 = 5.82 = 33.64;

4. Example #2 – Cont’d VAR(X) = E(X2) – [E(X)]2  37.6 – 33.64 = 3.96;
 = 3.96 = 1.99.