IndexError: list index out of range

[BoaCoder3]

I'm trying to make a program that can work out a mathematical ratio problem and then take the square root of the answer. To achieve the multiplication part i'm trying to make empty lists to which i add the numbers the user enters to define the ratio, then multiplying the list elements with each other. However, when i tried to run the program, this is what i got:

Error:
first set: 8
Traceback (most recent call last):
  File "C:/root to file...", line 13, in <module>
    data_procesing()
  File "C:/root to file...", line 9, in data_procesing()
    a = parameters[0] * parameters[1]
IndexError: list index out of range

Process finished with exit code 1

this is the program:

def data_procesing():

    while True:
        first_set = raw_input('first_set: ')
        for i in xrange(1, 2):
            parameters = []
            parameters.append(first_set)

            a = parameters[0] * parameters[1]
            print a


data_procesing()

First i had the parameters = [] loop outside the function so i thought this might be a scope problem, so i put it inside the for loop, however, that didn't work either, Can anybody please tell me what i'm doing wrong? is it perhaps impossible to multiply list elements like i did?

[stranac]

parameters = []
parameters.append(first_set)

At this point, the list only has one element (first_set).
Trying to access its second element (parameters[1]) results in IndexError.

[BoaCoder3]

Oh yes of course, what was i thinking, thanks a million!