Procter & Gamble Co. stock tumbled last week on a downbeat quarterly earnings report and glum news about its near-term business outlook. It reported fiscal third-quarter earnings fell 11% compared to a year ago, in line with a profit warning issued in March. It also warned sales volume would likely grow 5% to 7% in the fourth quarter, not the 7% to 8% it forecast a month ago. The stock was downgraded by two security analysts after the announcements. In trading Friday, P&G closed at $59.75, off 13.33% for the week.