In an experiment on the detection of cosmic rays a detector counts particles with different energies coming from different directions. The observed spectrum of the particles is shown in table below.
| Energy, MeV | 0-10 | 10-20 | 20-30 | 30-40 | 40-50 | 50-60 | 60-70 | 70-80 | 80-90 |
|---|---|---|---|---|---|---|---|---|---|
| # of p. | 15 | 71 | 75 | 68 | 39 | 17 | 10 | 4 | 1 |
At the significance level 0.05, test the hypothesis that the particle spectrum is distributed according to the Poisson distribution with parameter \(\lambda\). Find the effective estimate for \(\lambda\).