Considering the linear correlation coefficient values r there collected, it 
is evident that the variables are positively correlated: high value of the 
one corresponding to high value of the other. 
The correlation between ground control errors (71) and plotting errors 
(v3) 1s very low. On the contrary the correlations found out between 
ground control errors (1) and residual y-parallaxes (22) and between resi- 
dual y-parallaxes (2) and plotting errors (vs) are more evident. Anyway 
the r-values are statistically no significants. 
The degree of dependence of the plotting errors (vs) from the ground 
control erros (7) and the deformation of photogrammetric model by 
J-parallaxes (7e) has been confirmed by the multiple correlation coefficient 
Rs, 1» for the 0.1 per cent significance points. 
3. 
Proceeding in the statistical analysis of the data collected by Mr. Le 
Divelec, we have determined the degree of linear dependence between 
the total mean square errors of the ground control and total accuracy 
of plotting check points. This determination has been carried out com- 
puting by (1) the correlation coefficient r between the corresponding 
pairs of observations collected in columns 4 and 11 of the said Table I. 
The value of correlation coefficient obtained is 7 — 0.020 and its test of 
significances is + = 0.096 with 23 degrees of freedom. 
At the same time we have determined also the coefficient of the regres- 
sion line: 
n n n 
nlXx.y;— (= x) (= y. 
(5) D i=1 i1 (i1 / 
n n \ 2 
nlx [: x) 
i=l j=] / 
where x, y are respectively the values of the ground control errors and 
of the plotting accuracy, and z is the number of observations. 
eo 2 
The value of the regression coefficient is / — — 0.0061. Its significance 
with respect to a hypothetical value of 8 = 0 has been proved through 
the formula: 
(6) OR 0-5