196 



FIXING METER RATES 



These figures were made up by approximate methods, with 

 a few doubtful returns excluded. They are believed to repre- 

 sent the distribution fairly well and they check the total very 

 well, for they show 440 gallons per service on an average sold, 

 and adding the 140 gallons per service not accounted for, which 

 is the average from the total number, makes 580 gallons per 

 service. This checks approximately the 575 gallons first found. 



The data represented by the above brief statement have 

 been otherwise arranged and are plotted on a diagram which 

 is presented herewith (Fig. 22). This diagram shows the per- 

 centage of the total number of consumers taking more than 

 various quantities of water daily, arranged in a number of dif- 

 ferent ways. A dotted line shows them averaged by the gross 

 numbers in the systems for which the statistics were reasonably 

 complete. A broken line shows them averaged by systems, 

 which, as above noted, gives one small system the same relative 

 weight in the average as one large one. Three other solid 

 lines show the figures arranged in the order of size, the middle 

 one being the medium, so selected that half the results fall 

 below it and half above it, while the two lines marked as the 

 normal 10 per cent limit and the normal 90 per cent limit are 

 the lines which include 80 per cent of all the results. Ten per 



