The voluble talk-show host Andrea Legarreta broke from her routine of celebrity chatter and household tips recently to give her television viewers an impromptu lesson in global economics and the Mexican peso. “The world economy has to do with what is going on with the Chinese economy, ob-vious-ly,” Ms. Legarreta, the host of the popular morning program “Hoy,” said, knowingly drawing out the last few syllables. With growth slowing in China, she added, “this generates nervousness in the whole world.” Her co-host, Raúl Araiza, chimed in: “One of the effects in Mexico is that the dollar costs just a bit more than it ... (full story)