Finding the Fourth Proportional to 1,665.31, 2,297.72 and 1,247.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,665.31 : 2,297.72 = 1,247.05 : x
2. Step 2: Convert to fraction form
   1,665.31/2,297.72 = 1,247.05/x
3. Step 3: Cross multiply
   1,665.31x = 2,297.72 × 1,247.05
4. Step 4: Simplify right side
   1,665.31x = 2,865,357.78
5. Step 5: Solve for x
   x = 2,865,357.78/1,665.31
6. Step 6: Final answer
   x = 1,720.62