Finding the Fourth Proportional to 1,421.89, 1,962.21 and 824.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,421.89 : 1,962.21 = 824.50 : x
2. Step 2: Convert to fraction form
   1,421.89/1,962.21 = 824.50/x
3. Step 3: Cross multiply
   1,421.89x = 1,962.21 × 824.50
4. Step 4: Simplify right side
   1,421.89x = 1,617,828.21
5. Step 5: Solve for x
   x = 1,617,828.21/1,421.89
6. Step 6: Final answer
   x = 1,137.81