Question 201356
L= 2C +1.57(D+d) + (D+d) / (4C)
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Please  check  to  assure  this  is  the  problem
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substituting,  C=19,  D= 8,,d= 5
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L = 2(19) +1.57{ (8) +(5) } + { (8) + (5) } / { 4(19) }
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L= 38 +1.57(13) + (13)/ (76)
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L= 38 + 20.41 + .1711
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L = 58.58