Answer:
Decline percentage = 64.29%
Step-by-step explanation:
First find the margin call price = Initial price x (1 - initial margin) / (1-maintenance margin)
Margin call price = 68 x ( 1- 75%) / (1 - 30%)
Margin call price = $24.29
The margin call that the investor will have if the price fall to $24.29.
Now find the percentage decline:
Percentage decline = (68 - 24.29) / 68
Percentage decline = 0.6429
Thus decline percentage = 64.29%