Finding the Fourth Proportional to 1,314.48, 1,971.89 and 389.91

Step by Step Solution

1. Step 1: Write the proportion equation
   1,314.48 : 1,971.89 = 389.91 : x
2. Step 2: Convert to fraction form
   1,314.48/1,971.89 = 389.91/x
3. Step 3: Cross multiply
   1,314.48x = 1,971.89 × 389.91
4. Step 4: Simplify right side
   1,314.48x = 768,868.73
5. Step 5: Solve for x
   x = 768,868.73/1,314.48
6. Step 6: Final answer
   x = 584.92