Final answer:
The correct calculation to find the lower bound for 9.4 x 7.3, when rounded to one decimal place, is 9.0 x 7.0.
Step-by-step explanation:
The correct calculation to find the lower bound for 9.4 x 7.3, when both numbers have been rounded to one decimal place, is option b) 9.0 x 7.0.
When you round 9.4 to one decimal place, it becomes 9.0. Similarly, when you round 7.3 to one decimal place, it becomes 7.0.
By multiplying 9.0 and 7.0, you get the lower bound for 9.4 x 7.3.