Final answer:
To find the total distance Lauren ran, we add 2.76 miles and 0.4 miles together, resulting in 3.16 miles. The correct model representing this sum is '3 ones, 16 tenths'.
Step-by-step explanation:
The question asks for the model that represents the sum of the number of miles Lauren ran after she ran 2.76 miles in a track event and then 0.4 mile home. To find the total distance, we need to add these two numbers together.
2.76 miles + 0.4 miles = 3.16 miles
Accordingly, the correct choice that models the total distance Lauren ran is C. 3 ones, 16 tenths. This is because 3 ones (or 3 whole miles) and 16 tenths (which are 1.6 miles when converted) combine to make 3.16 miles.