Ott and Longnecker (2001) present an example in which the number of cell clumps per algae species was fitted to a Poisson distribution. A lake sample was analyzed to determine the number of clumps of cells per microscope field. The data are summarized below for 150 fields examined.

Here, xi denotes the number of cell clumps per field, and ni denotes the frequency of occurrence of fields of each cell clump count.

xi 0 1 2 3 4 56 ≤ 7 ni 6 23 29 31 27 13 8 13 Write a SAS program to perform a chi-square goodness-of-fit at α = 0.05 to test the hypothesis that the observed counts were drawn from a Poisson probability distribution.