Finding the Fourth Proportional to 1,365.20, 1,883.90 and 775.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,365.20 : 1,883.90 = 775.72 : x
2. Step 2: Convert to fraction form
   1,365.20/1,883.90 = 775.72/x
3. Step 3: Cross multiply
   1,365.20x = 1,883.90 × 775.72
4. Step 4: Simplify right side
   1,365.20x = 1,461,376.14
5. Step 5: Solve for x
   x = 1,461,376.14/1,365.20
6. Step 6: Final answer
   x = 1,070.45