Can you assist with the following question and illustrate how to solve it? It doesn't provide a risk-free rate, so I'm not sure if its necessary to have one in order to determine if there is an arbitrage opportunity.

Consider a forward contract on IBM requiring purchase of a share of IBM stock for $150 in six months. The stock currently sells for $140 a share. Assume that it pays no dividends over the coming six months. Six-month zero-coupon bonds are selling for $98 per $100 of face value.

a. If the forward is selling for $10.75, is there an arbitrage opportunity? If so, describe exactly how you could take advantage of it.