Finding the Fourth Proportional to 1,384.86, 1,910.55 and 971.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,384.86 : 1,910.55 = 971.10 : x
2. Step 2: Convert to fraction form
   1,384.86/1,910.55 = 971.10/x
3. Step 3: Cross multiply
   1,384.86x = 1,910.55 × 971.10
4. Step 4: Simplify right side
   1,384.86x = 1,855,335.11
5. Step 5: Solve for x
   x = 1,855,335.11/1,384.86
6. Step 6: Final answer
   x = 1,339.73