Finding the Fourth Proportional to 1,314.37, 1,971.56 and 390.00

Step by Step Solution

1. Step 1: Write the proportion equation
   1,314.37 : 1,971.56 = 390.00 : x
2. Step 2: Convert to fraction form
   1,314.37/1,971.56 = 390.00/x
3. Step 3: Cross multiply
   1,314.37x = 1,971.56 × 390.00
4. Step 4: Simplify right side
   1,314.37x = 768,896.59
5. Step 5: Solve for x
   x = 768,896.59/1,314.37
6. Step 6: Final answer
   x = 584.99