Finding the Fourth Proportional to 1,372.69, 1,894.31 and 783.21

Step by Step Solution

1. Step 1: Write the proportion equation
   1,372.69 : 1,894.31 = 783.21 : x
2. Step 2: Convert to fraction form
   1,372.69/1,894.31 = 783.21/x
3. Step 3: Cross multiply
   1,372.69x = 1,894.31 × 783.21
4. Step 4: Simplify right side
   1,372.69x = 1,483,644.49
5. Step 5: Solve for x
   x = 1,483,644.49/1,372.69
6. Step 6: Final answer
   x = 1,080.83