Finding the Fourth Proportional to 1,242.56, 1,716.12 and 800.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,242.56 : 1,716.12 = 800.72 : x
2. Step 2: Convert to fraction form
   1,242.56/1,716.12 = 800.72/x
3. Step 3: Cross multiply
   1,242.56x = 1,716.12 × 800.72
4. Step 4: Simplify right side
   1,242.56x = 1,374,131.61
5. Step 5: Solve for x
   x = 1,374,131.61/1,242.56
6. Step 6: Final answer
   x = 1,105.89