Finding the Fourth Proportional to 378,123, 521,820.72 and 208,368.06

Step by Step Solution

1. Step 1: Write the proportion equation
   378,123 : 521,820.72 = 208,368.06 : x
2. Step 2: Convert to fraction form
   378,123/521,820.72 = 208,368.06/x
3. Step 3: Cross multiply
   378,123x = 521,820.72 × 208,368.06
4. Step 4: Simplify right side
   378,123x = 108,730,771,094.20
5. Step 5: Solve for x
   x = 108,730,771,094.20/378,123
6. Step 6: Final answer
   x = 287,553.97