Finding the Fourth Proportional to 1,408.15, 2,109.92 and 938.76

Step by Step Solution

1. Step 1: Write the proportion equation
   1,408.15 : 2,109.92 = 938.76 : x
2. Step 2: Convert to fraction form
   1,408.15/2,109.92 = 938.76/x
3. Step 3: Cross multiply
   1,408.15x = 2,109.92 × 938.76
4. Step 4: Simplify right side
   1,408.15x = 1,980,695.89
5. Step 5: Solve for x
   x = 1,980,695.89/1,408.15
6. Step 6: Final answer
   x = 1,406.59