Finding the Fourth Proportional to 1,210.31, 1,669.30 and 837.91

Step by Step Solution

1. Step 1: Write the proportion equation
   1,210.31 : 1,669.30 = 837.91 : x
2. Step 2: Convert to fraction form
   1,210.31/1,669.30 = 837.91/x
3. Step 3: Cross multiply
   1,210.31x = 1,669.30 × 837.91
4. Step 4: Simplify right side
   1,210.31x = 1,398,714.82
5. Step 5: Solve for x
   x = 1,398,714.82/1,210.31
6. Step 6: Final answer
   x = 1,155.67