Finding the Fourth Proportional to 1,312.74, 1,968.72 and 388.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,312.74 : 1,968.72 = 388.12 : x
2. Step 2: Convert to fraction form
   1,312.74/1,968.72 = 388.12/x
3. Step 3: Cross multiply
   1,312.74x = 1,968.72 × 388.12
4. Step 4: Simplify right side
   1,312.74x = 764,099.61
5. Step 5: Solve for x
   x = 764,099.61/1,312.74
6. Step 6: Final answer
   x = 582.06