Final answer:
47.6 seconds (400 m -Women) is the least precise world record time among the options given, as it has the fewest significant figures.
Step-by-step explanation:
The question asks which of the following world record times from Track and Field is least precise:
- A. 47.6 seconds (400 m -Women)
- B. 43.18 seconds (400 m - Men)
- C. 21.34 seconds (200 m-Women)
- D. 9.79 seconds (100 m - Men)
To answer this, we examine the number of significant figures in each time. The least precise measurement would be the one with the fewest significant figures. Option A has only three significant figures (47.6), while the others have four (43.18, 21.34, and 9.79). Therefore, the world record time that is least precise is 47.6 seconds for the 400 m women's event.
Precision in times is typically related to the number of decimal places to which the time is measured. In Track and Field, as in other sports, timing systems with a greater number of decimal places can differentiate more finely between competitors' times, helping to resolve closer races. However, the manual timing provided in option A lacks the granularity of the automatic timing system suggested by other options due to fewer significant figures.