data FitMiss;
       input Oxygen RunTime RunPulse @@;
       datalines;
    44.609  11.37  178     45.313  10.07  185
    54.297   8.65  156     59.571    .      .
    49.874   9.22    .     44.811  11.63  176
      .     11.95  176          .  10.85    .
    39.442  13.08  174     60.055   8.63  170
    50.541    .      .     37.388  14.03  186
    44.754  11.12  176     47.273    .      .
    51.855  10.33  166     49.156   8.95  180
    40.836  10.95  168     46.672  10.00    .
    46.774  10.25    .     50.388  10.08  168
    39.407  12.63  174     46.080  11.17  156
    45.441   9.63  164       .      8.92    .
    45.118  11.08    .     39.203  12.88  168
    45.790  10.47  186     50.545   9.93  148
    48.673   9.40  186     47.920  11.50  170
    47.467  10.50  170
    ;
proc mi data=FitMiss noprint out=outmi seed=3237851;
      var Oxygen RunTime RunPulse;
   run;
proc reg data=outmi outest=outreg covout noprint;
      model Oxygen= RunTime RunPulse;
      by _Imputation_;
   run;
proc mianalyze data=outreg;
      modeleffects Intercept RunTime RunPulse;
   run;