Finding the Fourth Proportional to 2,239.76, 3,090.92 and 1,231.50

Step by Step Solution

1. Step 1: Write the proportion equation
   2,239.76 : 3,090.92 = 1,231.50 : x
2. Step 2: Convert to fraction form
   2,239.76/3,090.92 = 1,231.50/x
3. Step 3: Cross multiply
   2,239.76x = 3,090.92 × 1,231.50
4. Step 4: Simplify right side
   2,239.76x = 3,806,461.82
5. Step 5: Solve for x
   x = 3,806,461.82/2,239.76
6. Step 6: Final answer
   x = 1,699.50