In the business world, scandals have rocked the mutual fund industry. Yesterday, the nation’s fifth largest mutual fund company, Putnam, announced its chief executive, Lawrence Lasser, would be stepping down. Federal and state prosecutors have recently accused the company of fraud. Also yesterday, the head governmental official with the New England office of the Securities and Exchange Commission, Juan Marcelino, announced he would step down in part because his office failed to investigate problems at Putnam. Meanwhile, in congressional testimony, regulators estimated one of out every four major mutual fund brokers has been involved in illegal trading. Some 95 million Americans now have mutual fund accounts worth a total of $7 trillion.