Finding the Fourth Proportional to 1,564.31, 2,158.76 and 856.17

Step by Step Solution

1. Step 1: Write the proportion equation
   1,564.31 : 2,158.76 = 856.17 : x
2. Step 2: Convert to fraction form
   1,564.31/2,158.76 = 856.17/x
3. Step 3: Cross multiply
   1,564.31x = 2,158.76 × 856.17
4. Step 4: Simplify right side
   1,564.31x = 1,848,265.55
5. Step 5: Solve for x
   x = 1,848,265.55/1,564.31
6. Step 6: Final answer
   x = 1,181.52