Numeracy questions are on page 20 here https://www.rand.org/content/dam/rand/pubs/working_papers/WR...

People who score well on probability numeracy are likely better educated and better paid and have more in automatic savings plans. So if someone is maxing out their 401k they don’t feel they need to save more.

The article shows that in the US there is a 25 point gap between high and low income on savings regret, and a 14 point gap between high and low numeracy scores.

In Singapore where savings are more automatic numeracy is a more powerful predictor.