def get_Zstar(x_segment, y_segment, x_int, y_int, slope, n):
    """
    input: x_segment, y_segment, x_int, y_int, slope, n
    output: Z* (Arai plot zigzag parameter (alternate))
    """
    total = 0
    first_time = True
    for num, x in enumerate(x_segment):
        b_wiggle = get_b_wiggle(x, y_segment[num], y_int)
        result = 100 * ( old_div((x * abs(b_wiggle - abs(slope)) ), abs(y_int)) )
        total += result
        first_time = False
    Zstar = (old_div(1., (n - 1.))) * total
    return Zstar