Answer:
As the salesperson person gave the offer to Peter which he was not sure about, Peter said that he will come back in an hour but Peter didn't came instead his neighbour Sean came and asked salesperson to buy that boat on the price he told to person to according to the rule of offer this offer was made to Peter not Sean. If Peter would have accepted it then salesperson and Peter would be in contract but in this case now the offeror is Sean and Offeree if salesperson so it is up to him to accept the offer. Until the salesperson does not accept the offer then contract has not been form. If the salesperson accepts the offer of 35,750 then the contract will be formed.