The method of internal normalization was chosen to determine the mass of a sample comprising a mixture of four esters of butanoic acids. To this end, a reference solution containing known % mass of these esters led to the following relative values of the response coefficients often butanoates of methyl (ME), of ethyl (EE) and of propyl (PE), all three in ratio with butyl-butanoate (BE) KME/BE=0.919 KEE/BE=0.913, KPE/BE=1.06 From the chromatogram of the sample under analysis, reproduced below, and the information given in the table, find the mass composition of this mixture (ignore the first peak at 0.68 min)