Finding the Fourth Proportional to 1,200.10, 1,656.89 and 919.81

Step by Step Solution

1. Step 1: Write the proportion equation
   1,200.10 : 1,656.89 = 919.81 : x
2. Step 2: Convert to fraction form
   1,200.10/1,656.89 = 919.81/x
3. Step 3: Cross multiply
   1,200.10x = 1,656.89 × 919.81
4. Step 4: Simplify right side
   1,200.10x = 1,524,023.87
5. Step 5: Solve for x
   x = 1,524,023.87/1,200.10
6. Step 6: Final answer
   x = 1,269.91