Amazon.com Inc.’s first-quarter results sent a jolt into the fortune of Jeff Bezos Friday, making him richer than three of the four Wal-Mart heirs, according to the Bloomberg Billionaires Index. The online shopping giant increased sales 15 percent, beating analysts expectations, and broke out results for its Web Services cloud computing unit for the first time. The jump puts him on par with Wal-Mart founder Sam Walton’s daughter-in-law, Christy Walton, the richest woman in the U.S.