Interpret the following sine regression model.
y = 0.884 sin(0.245x - 1.093) + 0.400
what is the value of a in this equation?

The question is incomplete, so I will describe the sine regression model.

The function

y = 0.884 sin(0.245x - 1.093) + 0.400

correspond to the general equation:

y = a sin(bx - c) + d

where:

a = 0.884

b = 0.245

c = 1.093

d = 0.400

The amplitude of the function is computed as follows:

amplitude = |a| = 0.884

The period of the function is computed as follows:

period = 2π/|b| = 25.6456

The phase shift of the function is computed as follows:

phase shift = c/b = 4.4612 to the right (because there is a minus sign before c in the equation)

The vertical shift of the function is computed as follows:

vertical shift = d = 0.400