Answer: First, we need to convert 0.4 mile to feet by multiplying it by 5,280:
0.4 mile * 5,280 feet/mile = 2,112 feet
Next, we can use the formula for the circumference of a circle, C = 2πr, where C is the circumference and r is the radius.
We know that the distance around the circular track is 2,112 feet, so we can set up the equation:
2πr = 2,112
Simplifying the equation, we can divide both sides by 2π:
r = 2,112 / (2π)
Using π = 3.14 and rounding to the nearest hundredth, we get:
r ≈ 336.31 feet
Therefore, the radius of the track is approximately 336.31 feet.
Answer: 336.31 feet