As we pack more transistors into a tiny silicon chip, the cost of building a microprocessor "fab, " short for fabrication plant, will get more expensive.  Mr. Arthur Rock comes up with his own law based on Moore's Law.

"A very small addendum to Moore’s Law is Rock’s Law which says that the cost of capital equipment to build semiconductors will double every four years."
-Arthur Rock

The equation for Rock’s Law is:

Cn = Co ´ 2ⁿ

Where

Co = cost at the beginning year

Cn = cost in the future ‘nth’ year

n = (number of years from the beginning year to the 'nth' year)/4

The cost of building a 386-microprocessor fab was estimated to be about $500 million in 1988. How much would a Pentium II plant cost in 1997?

Cn = $500 million ´ 2^2.25

= $500 million ´4.76

= $2.378 billion

What would a new fab cost for the Intel Micro 2012 microprocessor in year 2012?

Estimate the answer:

Less than $2 billion 
Between $2 and $5 billion
Over $5 billion