Not really a homework question, but a problem I don't get nonetheless.(adsbygoogle = window.adsbygoogle || []).push({});

The density of fragments lying x kilometers from the center of a volcanic eruption is given by:

D(r) = 1/[sqrt(x) +2] fragments per square kilometer. To 3 decimal places, how many fragments will be found within 10 kilometers of the eruption's center?

I thought I was supposed to integrate the function from 0 to 100*pi, and in doing so I got 26.294, (I got 2[sqrt(x) - 2*ln(sqrt(x)+2)] when i integrated the function) but the answer was given to me as 70.424. The answer could very well be wrong, but I don't know that it is. What, if anything, am I doing wrong here?

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# Homework Help: Probability Density Function

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