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3 years ago

Please help #8 thank u

Mathematics

2 answers:

sweet [91]3 years ago

7 0

B because it says 45 of 60 is equal to 75%, so in fraction form it would be 75/100 = 45/60

exis [7]3 years ago

4 0

The answer is B because it is saying that 45/60=75%, so 75/100 = 45/60

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Answer:

See steps below

Step-by-step explanation:

Let X be the random variable that measures the lifespan of a bulb.

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• If the bulb is in good condition at the end of 18 months, what is the probability that the bulb will be in good condition at the end of 24 months?

Let A and B be the events,

A = “The bulb will last at least 24 months”

B = “The bulb will last at least 18 months”

We want to find P(A | B).

By definition P(A | B) = P(A∩B)P(B)

but B⊂A, so A∩B = B and

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Now the probability that exactly k bulbs need replacement is

$\bf \binom{6}{k}(0.39347)^k(1-0.39347)^{6-k}$

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This means that,

Probability that at least one of them needs replacement at the first inspection =

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