Finding the Fourth Proportional to 1,290.52, 1,780.36 and 824.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,290.52 : 1,780.36 = 824.50 : x
2. Step 2: Convert to fraction form
   1,290.52/1,780.36 = 824.50/x
3. Step 3: Cross multiply
   1,290.52x = 1,780.36 × 824.50
4. Step 4: Simplify right side
   1,290.52x = 1,467,906.82
5. Step 5: Solve for x
   x = 1,467,906.82/1,290.52
6. Step 6: Final answer
   x = 1,137.45