4. For a particular computer, the CPI for certain types of instructions is as follows: ALU operations, 2 cycles, make up 25% of dynamic (run-time) instruction count Load/store operations, 10 cycles, 30% of dynamic instruction count Control flow. 3 cycles, 20% of dynamic instruction count All other instructions, I cycle What is the average CPI? Suppose there is an optimization in which the CPI of load/store is reduced to 5, but cycle time is lengthened by 20%. What is the speedup due to this optimization