Finding the Fourth Proportional to 2,156.68, 2,976.42 and 1,225

Step by Step Solution

1. Step 1: Write the proportion equation
   2,156.68 : 2,976.42 = 1,225 : x
2. Step 2: Convert to fraction form
   2,156.68/2,976.42 = 1,225/x
3. Step 3: Cross multiply
   2,156.68x = 2,976.42 × 1,225
4. Step 4: Simplify right side
   2,156.68x = 3,646,114.50
5. Step 5: Solve for x
   x = 3,646,114.50/2,156.68
6. Step 6: Final answer
   x = 1,690.61