Finding the Third Proportional to 1,218,394 and 2,640,178

Step by Step Solution

1. Step 1: Write the proportion equation
   1,218,394 : 2,640,178 = 2,640,178 : x
2. Step 2: Convert to fraction form
   1,218,394/2,640,178 = 2,640,178/x
3. Step 3: Cross multiply
   1,218,394x = 2,640,178 × 2,640,178
4. Step 4: Simplify right side
   1,218,394x = 6,970,539,871,684
5. Step 5: Solve for x
   x = 6,970,539,871,684/1,218,394
6. Step 6: Final answer
   x = 5,721,088.48