Finding the Fourth Proportional to 1,312.50, 1,968.72 and 618.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,312.50 : 1,968.72 = 618.69 : x
2. Step 2: Convert to fraction form
   1,312.50/1,968.72 = 618.69/x
3. Step 3: Cross multiply
   1,312.50x = 1,968.72 × 618.69
4. Step 4: Simplify right side
   1,312.50x = 1,218,027.38
5. Step 5: Solve for x
   x = 1,218,027.38/1,312.50
6. Step 6: Final answer
   x = 928.02