You are trying to make a float number into a function:
(.05)(mb-50.00)
If you meant to multiply the two values, use *
:
(.05) * (mb-50.00)
Illustration:
>>> mb=51
>>> (.05)(mb-50.00)
Traceback (most recent call last):
File "", line 1, in
TypeError: 'float' object is not callable
>>> (.05)*(mb-50.00)
0.050000000000000003