[Tutor] Using Python for accurate calculations

[Gloom Demon]

Hello

I am working on a function which is going to calculate correlation
between two given sets of numbers.

Example:
x=[10.0, 10.8, 11.3, 10.0, 10.1, 11.1, 11.3, 10.2, 13.5, 12.3, 14.5, 11.0,
12.0, 11.8, 13.4, 11.4, 12.0, 15.6, 13.0, 12.1]
y=[0.70, 0.73, 0.75, 0.70, 0.65, 0.65, 0.70, 0.61, 0.70, 0.63, 0.70, 0.65,
0.72, 0.69, 0.78, 0.70, 0.60, 0.85, 0.80, 0.75]


However Python stores these numbers like this:
>>> x
[10.0, 10.800000000000001, 11.300000000000001, 10.0, 10.1, 11.1,
11.300000000000001, 10.199999999999999, 13.5, 12.300000000000001, 14.5,
11.0, 12.0, 11.800000000000001, 13.4, 11.4, 12.0, 15.6, 13.0, 12.1]
>>> y
[0.69999999999999996, 0.72999999999999998, 0.75, 0.69999999999999996,
0.65000000000000002, 0.65000000000000002, 0.69999999999999996,
0.60999999999999999, 0.69999999999999996, 0.63, 0.69999999999999996,
0.65000000000000002, 0.71999999999999997, 0.68999999999999995,
0.78000000000000003, 0.69999999999999996, 0.59999999999999998,
0.84999999999999998, 0.80000000000000004, 0.75]

The extra
digits added by Python are adding error probability to my
calculations. Is there a way to overcome this?

Thank You :-)
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