The average American believes they’ll need $1.26 million to retire comfortably, according to the 2025 Planning & Progress Study from Northwestern Mutual. But according to Grok, the artificial intelligence (AI) chatbot developed by Elon Musk-owned xAI, the actual amount needed depends on expenses, life expectancy and other sources of income. Read More: I Asked ChatGPT One Commonly Told Myth About Retiring — Here’s What It Said Find Out: 6 Popular SUVs That Aren't Worth the Cost -- and 6 Affordable Alternati ...