: THEORY OF STATISTICS. 
4. In fig. 50, suppose every horizontal array to be given a slide to the right 
until its mean lies on the vertical axis through the mean of the whole distribu- 
tion : then suppose the ellipses to be squeezed in the direction of this vertical 
axis until they become circles. The original quadrant has now become a 
sector with an angle between one and two right angles, and the question is 
solved on determining its magnitude, 
CHAPTER XVII. 
1. Estimated frequency 1554, standard error 0:28 lb. 2. Lower @, 
frequency 1472, standard error 0°26 1b. ; upper @, frequency 1116, standard 
error 0°34 1b. 3. 0°18 Ib. 4. 0-24 1b., 17 per cent. less than the standard 
error of the median. 5. 0 0196 in.or 0°76 per cent. of the standard-deviation : 
the standard error of the semi-interquartile range is 1:23 per cent. of that 
range. 
6. 7 n=100. n=1000. 
0-0 0-1 0°0316 
0:2 0-096 00304 
0-4 0-084 00266 
06 0-064 00202 
08 0°038 00114 
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