In a brief trading update, Pearson rode a stronger dollar to positive effect, since it gets sixty percent of its sales from the US. Penguin, while up, appears to have weakened in the past quarter: the more detailed report three months ago had sales at the unit for the first half of the year up 9 percent to 408 million pounds, but at the nine-month mark the company says sales are up 3 percent for the year to date on a constant-exchange-basis (and 6 percent on a “headline” basis). Pearson Education continues a strong year with sales up 10 percent. […]