Finding the Fourth Proportional to 2,061.35, 3,089.80 and 891.90

Step by Step Solution

1. Step 1: Write the proportion equation
   2,061.35 : 3,089.80 = 891.90 : x
2. Step 2: Convert to fraction form
   2,061.35/3,089.80 = 891.90/x
3. Step 3: Cross multiply
   2,061.35x = 3,089.80 × 891.90
4. Step 4: Simplify right side
   2,061.35x = 2,755,792.62
5. Step 5: Solve for x
   x = 2,755,792.62/2,061.35
6. Step 6: Final answer
   x = 1,336.89