Finding the Fourth Proportional to 1,421.71, 1,961.89 and 824.17

Step by Step Solution

1. Step 1: Write the proportion equation
   1,421.71 : 1,961.89 = 824.17 : x
2. Step 2: Convert to fraction form
   1,421.71/1,961.89 = 824.17/x
3. Step 3: Cross multiply
   1,421.71x = 1,961.89 × 824.17
4. Step 4: Simplify right side
   1,421.71x = 1,616,930.88
5. Step 5: Solve for x
   x = 1,616,930.88/1,421.71
6. Step 6: Final answer
   x = 1,137.31