What is the geometric mean of the values 4, 2, 4, 82?

8. Suppose a computer spends 90 percent of its time handling a particular type of computation when running a given program, and its manufactures make a change that improves its performance on that type of computation by a factor of 8.5. If the program originally took 100s to execute, what will its execution time be after the change?

9. A computer architect is designing the memory system for the next version of a processor. If the current version of the processor spends 80 percent of its time processing memory references, by how much must the architect speed up the memory system to achieve an overall speedup of 1.2?

10. What are the differences between IPC/CPI, MIPS and benchmark suit? Explain which one is the best performance metric and why?