Finding the Fourth Proportional to 2,128.21, 3,188.77 and 740.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,128.21 : 3,188.77 = 740.78 : x
2. Step 2: Convert to fraction form
   2,128.21/3,188.77 = 740.78/x
3. Step 3: Cross multiply
   2,128.21x = 3,188.77 × 740.78
4. Step 4: Simplify right side
   2,128.21x = 2,362,171.20
5. Step 5: Solve for x
   x = 2,362,171.20/2,128.21
6. Step 6: Final answer
   x = 1,109.93