Poisson distribution

[puzzleking123]

The number of typing errors per 1000 words made by a particular typist has a Poisson distribution with mean 2.5.~a. Find the probability that in a 4000 word script there will be at least 10 typing errors.~b. Using a suitable approximation determine the probability that there will be more than 24 errors in a 10000 word dissertation.

[factor-fiction]

Is this about fish?
This may help.
http://stattrek.com/lesson2/poisson.aspx
I'm not going to spend a lot of time on it for you because you generally never acknowledge my answers or queries and usually leave me (any others I know) feeling we have wasted our time

[Mosaic]

This is easy. Count the number of errors that occur over 10 random lines on each page. Calculate an average per page from this. Then divide this by 2.5 fish. Then gives thanks that your assessor goes on a public forum to find out how to mark your work, without reading it. At master's level, this must be a source of profound joy.

[factor-fiction]

If you have a reasonable attempt and post it on here I'll be happy to check it for you.
What course are you doing?

[twix123]

Factor....I thought that your link was to the Star Trek web site and I therefore looked up the Infinite Improbability Drive from the Hitchhikers Guide to the Galaxy (it made more sense than the statistical analysis course I did more than 25 years ago)!

[puzzleking123]

The prob of at least 10 errors in 4000 words is 0.542. There are 25 errors in 10000 words. Using Poisson distribution the prob of more than 24 is 0.526. I haven't got a clue how these values were achieved. That has what my friend has put. It is a statistic option we are doing.

[buildersmate]

I think we all recognised you were on the statistics course.
So you know the answer because your friend has told you, but you need to know how to work it out.
Have you read the link that F30 gave you? - that is the starting point to understand the principles of Poisson Distributions. Tables that enable to compute the answer for a particular Mean figure (2.5 in your case) are then available to work out easily the answer to your specific application.