Finding the Fourth Proportional to 1,071.76, 1,478.72 and 623.52

Step by Step Solution

1. Step 1: Write the proportion equation
   1,071.76 : 1,478.72 = 623.52 : x
2. Step 2: Convert to fraction form
   1,071.76/1,478.72 = 623.52/x
3. Step 3: Cross multiply
   1,071.76x = 1,478.72 × 623.52
4. Step 4: Simplify right side
   1,071.76x = 922,011.49
5. Step 5: Solve for x
   x = 922,011.49/1,071.76
6. Step 6: Final answer
   x = 860.28