Dear all:
 
I run ARIMA(1,0,1) by conditional maximum likelyhood.
the residual is :
 
table1:
uhat2
1980:01            
1980:02    -5.421687
1980:03    -0.506024
1980:04     1.867470
1980:05     1.698795
 
I choose the options /Graphs/--/Risidual correlogram/
output of Residual autocorrelation function shows:
 
table2:
 LAG      ACF          PACF          Q-stat. [p-value]
 
    1       0.1567        0.1567          0.1964  [0.658]
    2       -0.3373       -0.3710          1.5619  [0.458]
    3      -0.3194       -0.2244          4.0097  [0.260]
 
I caucualte Q-statistic by the formulation of Ljung-Box statistc from table1,
but the values I cauculate by myself  seem not equal to the values of table2 (0.1964, 1.5619, and 4.0097)
Maybe I mistake somewhere.
This question puzzles me.