Finding the Fourth Proportional to 1,978.29, 2,966.22 and 938.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,978.29 : 2,966.22 = 938.61 : x
2. Step 2: Convert to fraction form
   1,978.29/2,966.22 = 938.61/x
3. Step 3: Cross multiply
   1,978.29x = 2,966.22 × 938.61
4. Step 4: Simplify right side
   1,978.29x = 2,784,123.75
5. Step 5: Solve for x
   x = 2,784,123.75/1,978.29
6. Step 6: Final answer
   x = 1,407.34