According to new projections issued by market research firm NPD Group, Apple is poised to break its previous quarterly sales record. For the first time, Apple’s Mac unit sales are set to surpass the 4 million mark, with fourth quarter totals expected to fall in the range of 4.1 to 4.3 million. Apple’s new MacBook Air will apparently play a big role in Apple’s record-breaking quarter, and early demand for the sleek laptop makes solid sales a foregone conclusion. NPD’s numbers, if met, will represent remarkable year-over-year growth of approximately 22% to 28%. Apple is also expected to sell between 18.5 million and 19.5 million iPods during the December quarter.