Finding the Fourth Proportional to 1,398.71, 1,931.01 and 875.45

Step by Step Solution

1. Step 1: Write the proportion equation
   1,398.71 : 1,931.01 = 875.45 : x
2. Step 2: Convert to fraction form
   1,398.71/1,931.01 = 875.45/x
3. Step 3: Cross multiply
   1,398.71x = 1,931.01 × 875.45
4. Step 4: Simplify right side
   1,398.71x = 1,690,504.25
5. Step 5: Solve for x
   x = 1,690,504.25/1,398.71
6. Step 6: Final answer
   x = 1,208.61