Predictive distribution of poisson

Hi everyone,

Anyone got any ideas on how to do this?

The distribution of flaws along the length of an artificial fibre follows a Poisson

process, and the number of flaws in a length L is Po(L$\displaystyle \theta$ ). Very little is known about $\displaystyle \theta$ . The number of flaws in five fibres of lengths 10, 15, 25, 30 and 40 metres were found to be 3, 2, 7, 6, 10 respectively. Find the predictive distribution for the number of flaws in another piece of length 60 metres.

Thanks!