Answer:
[tex]P(X = 0) = 0.42[/tex]
[tex]P(X = 1) = 0.46[/tex]
[tex]P(X = 2) = 0.12[/tex]
Step-by-step explanation:
We have these following probabilities:
40% probability that the first file is corrupted. So 60% probability that the first file is not corrupted.
30% probability that the second file is corrupted. So 70% probability that the second file is not corrupted.
Probability mass function
Probability of each outcome(0, 1 and 2 files corrupted).
No files corrupted:
60% probability that the first file is not corrupted.
70% probability that the second file is not corrupted.
So
[tex]P(X = 0) = 0.6*0.7 = 0.42[/tex]
One file corrupted:
First one corrupted, second no.
40% probability that the first file is corrupted.
70% probability that the second file is not corrupted.
First one ok, second one corrupted.
60% probability that the first file is not corrupted.
30% probability that the second file is corrupted.
[tex]P(X = 1) = 0.4*0.7 + 0.6*0.3 = 0.46[/tex]
Two files corrupted:
40% probability that the first file is corrupted.
30% probability that the second file is corrupted.
[tex]P(X = 2) = 0.4*0.3 = 0.12[/tex]