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# Uni stats help watch

1. Anyone got a clue how to answer this question? I'm pretty sure I need to use the Poisson distribution formula, but other than that I'm stuck...

Any help would be greatly appreciated! 👍

Q5) A whale-watching boat goes out daily. The skipper notes that, on average, one whale is sighted during a 5 hour trip.

a)​What is the probability of seeing 3 or more whales during a 5 hour long trip?

b)​What is the probability that during a shorter trip of 2 hours that exactly 2 whales will be seen?

c)​Some tourists see a shark during their 5 hour boat trip. They are told that for 80% of the longer boat trips, no sharks are sighted at all. What is the probability of seeing at least one shark and at least one whale during a 5 hour boat trip?

d)​What assumption did you need to make to answer part c)?

e)​The skipper wants to know the average number of sightings of fish eagles in one week. The probability of having no sightings of fish eagles within one day is approximately 0.75. What is the average number of fish eagles sighted in one week (to nearest whole number)?

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2. (Original post by JellyCat99)
Q5) A whale-watching boat goes out daily. The skipper notes that, on average, one whale is sighted during a 5 hour trip.
X ~ Po(1).

(a) Can you compute P(X >= 3) = 1 - P(x < 3) = 1 - P(x <=2) using tables? If you don't have access to tables, then you can just sum up P(x=0) + P(X=1 +P(X=2) manually using the Poisson formula.

(b) 1 whale in 5 hours is the same as 2/5 whales in 2 hours so your new distribution is X ~ Po(2/5), can you now find P(X=2)?
3. Ahhh thanks, this makes sense!

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4. (Original post by JellyCat99)
Ahhh thanks, this makes sense!

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No problemo.

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