Raphael is training for a triathlon, a timed race that combines swimming, biking, and running. consider the following sentence: because his pool sessions are him swim more quickly, raphael plans to reduce by 1 hour per week the time he spends training on the bike and increase by 1 hour the time he spends in the swimming pool; however, his wife says that he should stop doing any biking and running and spend all 20 hours per week in the pool. which basic principle of individual choice does raphael's plan illustrate that his wife's advice does not

This is an example of marginal analysis, as the decisions made by Raphael are on margin.

Explanation:

The decision of Raphael about pool versus bike time is totally a "how-much decision". It is clear that pool time and bike time can both reduce the time for race. However, the efficiency of pool time is high currently, and hence there is much sense in trying to spend more time in the pool and less on bike. This however makes no sense that all the time is spent in the pool and no time biking. Raphael only intends to alter the number of hours spend on each activity at the margin.