Apple had another blowout quarter thanks to its new plus-size iPhones, which helped the company smash sales records for the holiday season. CEO Tim Cook said on a call with analysts that demand for the phones was “staggering,” and noted that results would have been even higher if not for the impact of the strong dollar on overseas sales. The midpoint of that range is just below the average estimate from analysts of $53.6 billion for the period ending in March, when sales typically fall from their holiday season peak. Apple Chief Financial Officer Luca Maestri said revenue for the current period will increase between 14 and 20 percent from a year ago, despite the strong dollar, which has forced other companies to lower their forecasts. The surge in sales of Apple’s signature smartphones helped make up for an expected decline in sales of iPad tablets. Sales of Mac computers rose 9 percent, and Apple saw overall revenue gains in all geographic regions. Apple doesn’t break out iPhone sales by country, but a report issued Tuesday by research firm Canalys estimates that Apple sold more smartphones than any other maker in China during the last quarter, including South Korea’s Samsung and the Chinese companies Huawei and Xiaomi. The stock has gained more than 50 percent over the last year, making Apple the world’s most valuable company with a market capitalization of $651 billion.