The mean thermal conductivity evaluated at the arithmetic mean tempera

1.	The mean thermal conductivity evaluated at the arithmetic mean temperature is represented by
A.	km = k0 [1 + β (t1 – t2)/2].
B.	km = k0 [1 + (t1 + t2)/2].
C.	km = k0 [1 + β (t1 + t2)/3].
D.	km = k0 [1 + β (t1 + t2)/2].
Answer» E.

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The mean thermal conductivity evaluated at the arithmetic mean temperature is represented by

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