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some areas might not be c“ eaned that shou”d be cleaned according to the
cleanup criteria.
Discussion
(1)

brought out the following

A telecommunication

points.

from Bruce Church on Enewetak Atoll (dated,

I believe, April 25, 1978; copy given to Bill Bair) indicated
additional

data were being taken and should be available within a

few days.

The message suggested

any decisions

be delayed until

these new data were available.
(2)

The scatter plot for Janet (Enjebi) does not suggest a bias in IMP
It was noted that Janet has been cleared of brush so

Am values.

that brush attenuation
corrections

of IMP Am readings did not occur.

have been made for brush

attenuation

Such corrections would tend to increase
this correction

No

to any islands.

IMP readings.

Whether

alone would remove the bias in the IMP readings

is unknown.
(3)

New IMP readings have been taken on Lucy and Alice because the
original readings were taken when the IMP was suffering from low
and high voltage problems.
desirable

(4)

New IMP readings on Belle are also

due to low voltage problems on original IMP survey.

It is my understanding
(statistician,

from discussions

with Madaline Barnes

DRI) that Frank Markwell probably

computed his

factor of 1.5 by taking the average of the five ratios (soil Am/IMP Am).
This method of computing an average ratio will usually give a higher
result than if one divides the average soil Am concentration by the
average

IMP Am concentration.

can be large if the statistical

Differences

between the two methods

distribution

of the individual ratios

is highly skewed, e.g., one or two ratios being much higher than
the others.

In this skewed case, the average of the individual

ratios will be influenced greatly by these high values, and to the
extent t’hat the high individual

ratios are not typical of most of

the data, the average ratio so computed will not be representative
of the bulk of the ratios.

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