Finding the Fourth Proportional to 1,678.01, 2,315.39 and 931.86

Step by Step Solution

1. Step 1: Write the proportion equation
   1,678.01 : 2,315.39 = 931.86 : x
2. Step 2: Convert to fraction form
   1,678.01/2,315.39 = 931.86/x
3. Step 3: Cross multiply
   1,678.01x = 2,315.39 × 931.86
4. Step 4: Simplify right side
   1,678.01x = 2,157,614.67
5. Step 5: Solve for x
   x = 2,157,614.67/1,678.01
6. Step 6: Final answer
   x = 1,285.82