Finding the Fourth Proportional to 1,312.71, 1,968.72 and 388.02

Step by Step Solution

1. Step 1: Write the proportion equation
   1,312.71 : 1,968.72 = 388.02 : x
2. Step 2: Convert to fraction form
   1,312.71/1,968.72 = 388.02/x
3. Step 3: Cross multiply
   1,312.71x = 1,968.72 × 388.02
4. Step 4: Simplify right side
   1,312.71x = 763,902.73
5. Step 5: Solve for x
   x = 763,902.73/1,312.71
6. Step 6: Final answer
   x = 581.93