A note on a moment test of fit for a mixture of two Poisson distributions

In this note a new moment test of fit for a mixture of two Poisson distributions is derived. The test is illustrated with (1) a classic data set of deaths per day of women over 80 as recorded in the Times newspaper for the years 1910 to 1912 and (2) a more recent data set concerned with foetal lamb movements. A small indicative size and power study is given.