Suppose that we have two machines A and B. The following table shows the execution times for programs that make up a benchmark suite for machine A, machine B, and a reference machine X.

Program	Exec time of X	Exec time of A	Exec time of B
P1	120	40	20
P2	300	100	150
P3	50	5	10
P4	150	25	30
P5	90	10	15

Calculate the overall speedup of machine A versus reference machine X, using geometric mean