Finding the Fourth Proportional to 1,317.63, 1,819.61 and 820.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,317.63 : 1,819.61 = 820.50 : x
2. Step 2: Convert to fraction form
   1,317.63/1,819.61 = 820.50/x
3. Step 3: Cross multiply
   1,317.63x = 1,819.61 × 820.50
4. Step 4: Simplify right side
   1,317.63x = 1,492,986.77
5. Step 5: Solve for x
   x = 1,492,986.77/1,317.63
6. Step 6: Final answer
   x = 1,133.08