"rb608" wrote in
news:v1EPf.40384$%I.25893@trnddc03:

"William Claspy" wrote in message
My guess was 6(pi) inches. It's C=pi(d), so if we add six inches to
d (which we had converted from feet to inches), we have C=pi(d+6).
Balances out with 6(pi). No?

No. You're thinking correctly, but you only got halfway there.
You're actually increasing the diameter by a whole foot (6 inches each
side).

Joe F.




c1=pi*(7926 miles)*5280(feet/mile)*12(inches/ft)
c2=pi*((7926 miles)*5280(feet/mile)*12(inches/ft)+12 inches)

c2-c1=37.69 inches


--
Scott
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