Finding the Fourth Proportional to 1,077.88, 1,618.05 and 429.07

Step by Step Solution

1. Step 1: Write the proportion equation
   1,077.88 : 1,618.05 = 429.07 : x
2. Step 2: Convert to fraction form
   1,077.88/1,618.05 = 429.07/x
3. Step 3: Cross multiply
   1,077.88x = 1,618.05 × 429.07
4. Step 4: Simplify right side
   1,077.88x = 694,256.71
5. Step 5: Solve for x
   x = 694,256.71/1,077.88
6. Step 6: Final answer
   x = 644.09