Finding the Fourth Proportional to 1,003.86, 1,505.58 and 345.68

Step by Step Solution

1. Step 1: Write the proportion equation
   1,003.86 : 1,505.58 = 345.68 : x
2. Step 2: Convert to fraction form
   1,003.86/1,505.58 = 345.68/x
3. Step 3: Cross multiply
   1,003.86x = 1,505.58 × 345.68
4. Step 4: Simplify right side
   1,003.86x = 520,448.89
5. Step 5: Solve for x
   x = 520,448.89/1,003.86
6. Step 6: Final answer
   x = 518.45