Finding the Fourth Proportional to 1,490.51, 2,056.86 and 861.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,490.51 : 2,056.86 = 861.05 : x
2. Step 2: Convert to fraction form
   1,490.51/2,056.86 = 861.05/x
3. Step 3: Cross multiply
   1,490.51x = 2,056.86 × 861.05
4. Step 4: Simplify right side
   1,490.51x = 1,771,059.30
5. Step 5: Solve for x
   x = 1,771,059.30/1,490.51
6. Step 6: Final answer
   x = 1,188.22