Finding the Fourth Proportional to 1,642.71, 2,265.39 and 1,224.09

Step by Step Solution

1. Step 1: Write the proportion equation
   1,642.71 : 2,265.39 = 1,224.09 : x
2. Step 2: Convert to fraction form
   1,642.71/2,265.39 = 1,224.09/x
3. Step 3: Cross multiply
   1,642.71x = 2,265.39 × 1,224.09
4. Step 4: Simplify right side
   1,642.71x = 2,773,041.25
5. Step 5: Solve for x
   x = 2,773,041.25/1,642.71
6. Step 6: Final answer
   x = 1,688.09