Abstract
We present an approximate method to compare the difference of the means of two groups of populations by indirect unpaired data. This indirect data structure occurs in receptor autoradiography, where the tissue distribution of receptors is visualized in the form of ligand bindings. This visualization is indirect because we can only observe and measure nonspecific bindings in one autoradiograph and total bindings in another autoradiograph. The distribution of receptors is obtained by subtracting the nonspecific bindings from the total bindings. Besides the reasoning of our method, an example is given using our experimental data.