Final answer:
The September wheat futures contract varied by 11.50 cents per bushel during today's trading, with the high being 810.00 cents and the low 798.50 cents per bushel.
Step-by-step explanation:
The September futures contract on wheat varied by 6 cents per bushel during today's trading. The question involves determining the variation in prices of a wheat futures contract during a single day's trading. According to the provided data, the September futures contract on wheat started the day at an open price of 804 cents per bushel.
The high during the day was 810 cents per bushel, and the low was 798.50 cents per bushel. To find the variance, we subtract the low price from the high price. Therefore, the September wheat futures contract varied by 11.50 cents per bushel (810.00 - 798.50 = 11.50) during the day's trading session.