In: Math
For X ~ BIN(20, 0.6), find the following probabilities (PLEASE SHOW CLEAR WORK):
P(X = 14) =
P(X > 15) =
P(X < 9) =
We have given ,
For X ~ BIN(20, 0.6),
P(X = 14) =C(20,14)*(0.6)^14*(1-0.6)^6
= 0.1244
or by using Excel command =BINOMDIST(14,20,0.6,FALSE) = 0.1244
P(X > 15) =P[X=16] + P[X=17] + P[X=18] + P[X=19] + P[X=20]
=0.035+0.0123+0.0031+0.0005+0..............by using calculated probabilities from below table
= 0.0509
by using Excel

= 1-0.9490 .........................................by using =BINOMDIST(15,20,0.6,TRUE)
=0.051
P(X < 9) =P[X=0] + P[X=1] + P[X=2] + P[X=3] +P[X=4] +P[X=5]+P[X=6]+P[X=7]+P[X=8]
=0+0+0+0+0.0003+0.0013+0.0049+0.0146+0.0355.................by using calculated probabilities from below table
=0.0566
by using Excel.

= 0.0566............................by using =BINOMDIST(8,20,0.6,TRUE)
By using formula C(n,r) (p)^r*(1-p)^n-r where n = 20 , p = 0.6 , x= 0 , 1 , 2 , ..........................20
| x | Pr[X = x] |
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0.0003 |
| 5 | 0.0013 |
| 6 | 0.0049 |
| 7 | 0.0146 |
| 8 | 0.0355 |
| 9 | 0.071 |
| 10 | 0.1171 |
| 11 | 0.1597 |
| 12 | 0.1797 |
| 13 | 0.1659 |
| 14 | 0.1244 |
| 15 | 0.0746 |
| 16 | 0.035 |
| 17 | 0.0123 |
| 18 | 0.0031 |
| 19 | 0.0005 |
| 20 | 0 |