Ex7-1 Two angles are measured with instruments having standard deviations s1 = 20" and s2 = 30"
(a) Which instrument is more precise?
(b) Find the relative weights of an angle measured by both instruments.
Solution :
(a) Higher the standard deviation, lower is the precision. Thus, instrument 1 (with s1 = 20" ) is more precise than instrument 2 (with s2 = 30").
(b) We know weights of measurement from an instrument are inversely proportional to variance. Thus
Thus, relative weights of observation from two instruments are w1 = 9 and w2 = 4