Question related to Moore's Law

[sotomie]

I need to solve this question ,I am not sure if i'm solving it right
q:In 1972, Intel 8008 microprocessor had 3500 transistors manufactured in 10 µm process while in 2006, Intel Itanium 2 processor contained 1.72 billion transistors using 90 nm process. Based upon these two data points only and assuming a constant doubling of transistor count in equal intervals of time, calculate the time interval it took to achieve doubling of transistor between the period 1971-2006.

My answer is 3.95*10^-8 years,which seems a bit weird!Any idea how this will be solved in accordance with Mooore's Law?
Thanks in advance.

 

[godfreyl]

1.72 billion / 3500 = 491 thousand.
2^19 = 524 thousand
So the number of transistors has doubled nearly 19 times.
35 years / 19 = 1.8 years

BTW, is it 1971 or 1972? You mentioned both dates.

 

[tpetar]

Wright's Law is More Accurate Than Moore's Law
http://www.tomshardware.com/news/moores-law-semiconductors-intel-chip,16734.html


Moore's Law is dead, says Gordon Moore
**broken link removed**