In: Statistics and Probability
Solution- To find Poisson distribution probabilities in Excel, use the function =POISSON(x;λ;0)
x=number of occurrences over a specified interval
λ=average number of occurrences over a specified interval = 20
since the probability distribution in excel for an interval of 30 minute duration given below.
x | p(X=x) | Round off at six places |
0 | 2.06115E-09 | 0 |
1 | 4.12231E-08 | 0 |
2 | 4.12231E-07 | 0 |
3 | 2.7482E-06 | 0.000003 |
4 | 1.3741E-05 | 0.000014 |
5 | 5.49641E-05 | 0.000055 |
6 | 0.000183214 | 0.000183 |
7 | 0.000523468 | 0.000523 |
8 | 0.001308669 | 0.001309 |
9 | 0.002908153 | 0.002908 |
10 | 0.005816307 | 0.005816 |
11 | 0.010575103 | 0.010575 |
12 | 0.017625171 | 0.017625 |
13 | 0.027115648 | 0.027116 |
14 | 0.03873664 | 0.038737 |
15 | 0.051648854 | 0.051649 |
16 | 0.064561067 | 0.064561 |
17 | 0.075954196 | 0.075954 |
18 | 0.084393552 | 0.084394 |
19 | 0.088835317 | 0.088835 |
20 | 0.088835317 | 0.088835 |
21 | 0.084605064 | 0.084605 |
22 | 0.076913695 | 0.076914 |
23 | 0.066881474 | 0.066881 |
24 | 0.055734561 | 0.055735 |
25 | 0.044587649 | 0.044588 |
26 | 0.034298192 | 0.034298 |
27 | 0.025406068 | 0.025406 |
28 | 0.018147191 | 0.018147 |
29 | 0.012515304 | 0.012515 |
30 | 0.008343536 | 0.008344 |
probability that no more then 14 customers will arrive = P(X<_14)
= probability sum of 0 to 14 of above table.
= 0.104864