Finding the Fourth Proportional to 1,987.91, 2,981.89 and 1,109.90

Step by Step Solution

1. Step 1: Write the proportion equation
   1,987.91 : 2,981.89 = 1,109.90 : x
2. Step 2: Convert to fraction form
   1,987.91/2,981.89 = 1,109.90/x
3. Step 3: Cross multiply
   1,987.91x = 2,981.89 × 1,109.90
4. Step 4: Simplify right side
   1,987.91x = 3,309,584.80
5. Step 5: Solve for x
   x = 3,309,584.80/1,987.91
6. Step 6: Final answer
   x = 1,664.86