Finding the Fourth Proportional to 1,382.86, 1,906.50 and 989.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,382.86 : 1,906.50 = 989.20 : x
2. Step 2: Convert to fraction form
   1,382.86/1,906.50 = 989.20/x
3. Step 3: Cross multiply
   1,382.86x = 1,906.50 × 989.20
4. Step 4: Simplify right side
   1,382.86x = 1,885,909.80
5. Step 5: Solve for x
   x = 1,885,909.80/1,382.86
6. Step 6: Final answer
   x = 1,363.77