Finding the Fourth Proportional to 1,917.86, 2,876.38 and 685.36

Step by Step Solution

1. Step 1: Write the proportion equation
   1,917.86 : 2,876.38 = 685.36 : x
2. Step 2: Convert to fraction form
   1,917.86/2,876.38 = 685.36/x
3. Step 3: Cross multiply
   1,917.86x = 2,876.38 × 685.36
4. Step 4: Simplify right side
   1,917.86x = 1,971,346.89
5. Step 5: Solve for x
   x = 1,971,346.89/1,917.86
6. Step 6: Final answer
   x = 1,027.89