Finding the Fourth Proportional to 1,237.50, 1,707.72 and 678.00

Step by Step Solution

1. Step 1: Write the proportion equation
   1,237.50 : 1,707.72 = 678.00 : x
2. Step 2: Convert to fraction form
   1,237.50/1,707.72 = 678.00/x
3. Step 3: Cross multiply
   1,237.50x = 1,707.72 × 678.00
4. Step 4: Simplify right side
   1,237.50x = 1,157,825.62
5. Step 5: Solve for x
   x = 1,157,825.62/1,237.50
6. Step 6: Final answer
   x = 935.62