40.28。 The coefficient of 36 periods is the coefficient of 40.28 corresponding to 25 periods. The calculation steps are as follows:

1, we can set a proportional equation: 36-period coefficient /36=25-period coefficient /25.

2. Bring the known value into the equation and get: 346/36=x/25, where x represents the coefficient of 25 periods.

3. By cross multiplication, the following calculation steps can be obtained: 346*25=36*x, 8650=36x, and by solving the equation, x=8650/36≈240.28. Coefficient is a mathematical term that refers to a constant or variable associated with a specific term in an algebraic expression. It represents the weight or proportional relationship of the items in the expression.