Finding the Fourth Proportional to 926.56, 1,386.72 and 780.50

Step by Step Solution

1. Step 1: Write the proportion equation
   926.56 : 1,386.72 = 780.50 : x
2. Step 2: Convert to fraction form
   926.56/1,386.72 = 780.50/x
3. Step 3: Cross multiply
   926.56x = 1,386.72 × 780.50
4. Step 4: Simplify right side
   926.56x = 1,082,334.96
5. Step 5: Solve for x
   x = 1,082,334.96/926.56
6. Step 6: Final answer
   x = 1,168.12