Finding the Fourth Proportional to 1,070.63, 1,606.10 and 421.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,070.63 : 1,606.10 = 421.31 : x
2. Step 2: Convert to fraction form
   1,070.63/1,606.10 = 421.31/x
3. Step 3: Cross multiply
   1,070.63x = 1,606.10 × 421.31
4. Step 4: Simplify right side
   1,070.63x = 676,667.90
5. Step 5: Solve for x
   x = 676,667.90/1,070.63
6. Step 6: Final answer
   x = 632.03