Mixed Analyte Performance Evaluation Program
                          Statistical Summary
 Sample Id:  MAPEP-94-W2
           Number Labs Sample   Grand     Grand       Mean %    Range    Range
Analyte     Reporting   Size     Mean     Std Dev     Bias      Min       Max
Aluminum      25         20    243.76     17.00       7.59    196.67    294.67   
Antimony      24         24    172.12     12.01       5.07    151.33    221.00
Arsenic       24         21     51.15      3.41       6.47     36.67     57.74
Barium        25         25    202.97      7.02       2.42    195.00    220.00
Beryllium     25         25     99.03      3.30       4.38     92.67    114.56
Cadmium       25         25    116.10      6.37       4.01    104.23    128.33
Calcium       25         25  21383.37   1032.38       3.37  18916.67  23717.33
Chromium      25         25    204.60      8.08       2.89    185.33    215.67
Cobalt        25         25    278.82      8.24       3.27    261.67    298.40
Copper        25         25    234.91      5.08       2.86    210.33    260.93
Iron          25         23    241.58     17.52       7.18    174.67    280.00
Lead          25         22    117.79      7.24       4.83    104.60    138.33
Magnesium     25         25  14914.32    832.92       3.38  13366.67  16904.00
Manganese     25         25    117.97      3.68       3.26     98.40    125.00
Nickel        25         25    162.20      9.19       4.79    149.00    183.53
Potassium     24         23   8377.36    560.90       4.79   6886.67   9363.33
Selenium      24         22     63.37      4.87       6.59     46.73     71.00
Sodium        24         23  10658.61    475.84       3.64   8937.33  11966.67
Thallium      24         17    117.01     14.11       5.71     91.97    134.33
Vanadium      24         22    102.07      2.35       4.10     89.00    116.63
Zinc          25         23    160.79      6.64       3.33    145.00    175.33
Cesium-137    23         23     25.22      1.29       3.85     23.17     27.40
Cobalt-57     22         21     81.51      3.45       3.49     75.00     87.47
Cobalt-60     23         23     11.95      0.55       3.26     10.57     12.73
Plutonium-239 20         19      0.48      0.03       5.60      0.44      0.53
Strontium-90  17         15      4.53      0.36       9.35      3.53      5.90

Sample size excludes outliers.
Outliers are defined as laboratory means with a bias greater than 30 percent.
Range minimum and maximum values refer to the laboratory means.


06/01/95                               Page 1