it takes an average of 40 seconds to download a certain file, with a standard deviation of 5 seconds. the actual distribution of the download time is unknown. using chebyshev's inequality, what can be said about the probability of spending more then 1 minute for this download ?

Question

anonymous · Answer

the probability of spending more then 1 minute is very low

anonymous · Answer

whats chebyshev's inequality?

tansheet · Answer

dont know .....

anonymous · Answer

thats great. you don't even understand your own question??

anonymous · Answer

well I can't help you sorry

tansheet · Answer

Chebyshev’s inequality (also spelled as Tchebysheff’s inequality) guarantees that in any data sample or probability distribution,"nearly all" values are close to the mean — the precise statement being that no more than 1/k2 of the distribution’s values can be more than k standard deviations away from the mean. The inequality has great utility because it can be applied to completely arbitrary distributions (unknown except for mean and variance), for example it can be used to prove the weak law of large numbers.

tansheet · Answer

now help me please.....

anonymous · Answer

i've no idea about chebyshev's inequality sorry dude.

phi · Answer

no more than $\frac{1}{k^2} $ of the distribution’s values can be more than k standard deviations away from the mean

So, first question is How many std dev away is 60 seconds from 40 seconds?

phi · Answer

(60-40)/5 = 4 std deviations away.  So according to Chebyshev, no more than 1/16 times will the download take more than a minute.

So, to answer the question, the probability of spending more then 1 minute for this download ?  I would say 1/16