Suppose you run a total of 4.35 miles in 58.75 minutes. If you want to determine your average running speed in units of km/hr, how many significant digits will your final answer have?

I would go with 3 set by the 4.35 miles.

To determine the average running speed in km/hr, we need to convert the distance and time to the appropriate units.

First, let's convert the distance from miles to kilometers. We know that 1 mile is equal to approximately 1.60934 kilometers. So, to convert 4.35 miles to kilometers, we can multiply it by 1.60934:

4.35 miles * 1.60934 km/mile = 6.988809 km

Next, let's convert the time from minutes to hours. We know that there are 60 minutes in an hour. So, to convert 58.75 minutes to hours, we can divide it by 60:

58.75 minutes ÷ 60 min/hr = 0.97916667 hr

Now, we can calculate the average running speed by dividing the distance by the time:

Average speed = Distance ÷ Time
= 6.988809 km ÷ 0.97916667 hr
= 7.13636... km/hr

The number of significant digits in the final answer depends on the number of significant digits in the original data.

In this case, the distance measurement of 4.35 miles has four significant digits, and the time measurement of 58.75 minutes has four significant digits as well. Therefore, when we perform the calculations, we should round the final answer to have the same number of significant digits, which is four.

Therefore, the final answer should have four significant digits: 7.136 km/hr.