Answer. Let Us First Discuss About Some Theory for this Question.
We Know that Performance Equation is given as :
CPU Time = Cycle Time * Instruction Count * Average CPI
Assuming n different type of Instructions each with count IC and requiring CPI cycles Then,
a) Average CPI= sum of (CPI * Frequency) of all the instructions.
b) Percentage execution Time spent by each class of Instructions is given by Frequency/Average CPI.
Here is the Image of Answers for both a) and b) Questions.
c) Enhanced Average CPI is calculated as follows:
d) Speed Up Factor is calculated as Average CPI(old)/Average CPI(Enhanced) i.e 4.15/4.65 = 0.89.