Find the missing number in the following series. (6, 12, 30, 90, ?, 1260)

Analyze the pattern: 6 to 12 (x2), 12 to 30 (x2.5), 30 to 90 (x3), 90 to ? (?), ? to 1260 (?). The multipliers are: 2, 2.5, 3, ... increasing by 0.5 each time. So the pattern should be: x2, x2.5, x3, x3.5, x4. Verifying: 6 x 2 = 12, 12 x 2.5 = 30, 30 x 3 = 90, 90 x 3.5 = 315, 315 x 4 = 1260. This confirms the missing number is 315.