Finding the Fourth Proportional to 1,267.50, 1,749.15 and 715.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,267.50 : 1,749.15 = 715.50 : x
2. Step 2: Convert to fraction form
   1,267.50/1,749.15 = 715.50/x
3. Step 3: Cross multiply
   1,267.50x = 1,749.15 × 715.50
4. Step 4: Simplify right side
   1,267.50x = 1,251,516.83
5. Step 5: Solve for x
   x = 1,251,516.83/1,267.50
6. Step 6: Final answer
   x = 987.39