Finding the Fourth Proportional to 2,739.78, 4,109.86 and 891.50

Step by Step Solution

1. Step 1: Write the proportion equation
   2,739.78 : 4,109.86 = 891.50 : x
2. Step 2: Convert to fraction form
   2,739.78/4,109.86 = 891.50/x
3. Step 3: Cross multiply
   2,739.78x = 4,109.86 × 891.50
4. Step 4: Simplify right side
   2,739.78x = 3,663,940.19
5. Step 5: Solve for x
   x = 3,663,940.19/2,739.78
6. Step 6: Final answer
   x = 1,337.31