Finding the Fourth Proportional to 1,434.45, 1,976.85 and 991.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,434.45 : 1,976.85 = 991.56 : x
2. Step 2: Convert to fraction form
   1,434.45/1,976.85 = 991.56/x
3. Step 3: Cross multiply
   1,434.45x = 1,976.85 × 991.56
4. Step 4: Simplify right side
   1,434.45x = 1,960,165.39
5. Step 5: Solve for x
   x = 1,960,165.39/1,434.45
6. Step 6: Final answer
   x = 1,366.49