Practical Least Squares

accidental errors adjusted values Adjustment of Observations angle equations approximate values arithmetic mean assumed best value central-point figure closure coefficients column condition equations constant term convenient corrections correlates corresponding curve derived equations determined diagonal differences of elevation discrepancies elimination empirical formula equa equal Error Curve errors of observation example function horizontal angles indicated indirect observations Law of Error Least Squares left-hand length logarithms logsin mean square error measured Method of Least multiplied normal equations number of conditions number of errors number of observations observation equations observation of weight observed quantity observed values obtain plotted precision probable error problem propagation of error quadrilateral readings reduced residuals satisfy set of observations side equation single observation slide-rule solution spherical excess station Substituting sum-term tion total number triangle true error unity unknown quantities V₁ vations w+b+r weighted mean write written zero