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36 votes
36 votes
The lifespan, in years, of a certain computer is exponentially distributed. The probability that its lifespan exceeds four years is 0.30. Let f(x) represent the density function of the computer's lifespan, in years, for x>0. Determine an expression for f(x).

User Santosh Jadi
by
2.9k points

1 Answer

23 votes
23 votes

Answer:

The correct answer is "
0.300993e^(-0.300993x)".

Explanation:

According to the question,


P(x>4)=0.3

We know that,


P(X > x) = e^((-\lambda* x))


e^((-\lambda* 4)) = 0.3


\lambda = 0.300993

Now,


f(x) = \lambda e^(-\lambda x)

By putting the value, we get


=0.300993e^(-0.300993x)

User Stanislav Lukyanov
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3.0k points