A random-sequence polyribonucleotide produced by polynucleotide phosphorylase, with CDP and ADP in a 5:1 molar ratio stimulated the incorporation of proline, histidine, threonine, glutamine, asparagine, and lysine in a cell-free translation system in the following proportions: 100, 23.4, 20, 3.3, 3.3, and 1.0, respectively. What does this experiment reveal about the nucleotide composition of coding triplets for these six amino acids?