Finding the Fourth Proportional to 1,316.55, 1,972.17 and 612.76

Step by Step Solution

1. Step 1: Write the proportion equation
   1,316.55 : 1,972.17 = 612.76 : x
2. Step 2: Convert to fraction form
   1,316.55/1,972.17 = 612.76/x
3. Step 3: Cross multiply
   1,316.55x = 1,972.17 × 612.76
4. Step 4: Simplify right side
   1,316.55x = 1,208,466.89
5. Step 5: Solve for x
   x = 1,208,466.89/1,316.55
6. Step 6: Final answer
   x = 917.90