For this study the degree of freedom is two (i.e. v1=v2=10). A suitable level of significant set for the two sided test
is 0.1(i.e. 10%), this means that the probability of accepting the Null Hypothesis is 90%. The F distribution at significant level =0.05, with v1=10 and v2=10 from the Percentile table is 2.99. The next stage is to compute the values of the F statistics. Ground Survey method is considered to have the smallest error vector (0.000) and hence this value has been taken as s2 and orthophoto measurement is taken as s1 in turn. As an illustration to compute the F statistics between Ground survey (i.e. s2=0.000) and orthophoto (i.e. s1=0.406), we have the solution as: