Finding the Fourth Proportional to 1,109.50, 1,528.46 and 777.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,109.50 : 1,528.46 = 777.30 : x
2. Step 2: Convert to fraction form
   1,109.50/1,528.46 = 777.30/x
3. Step 3: Cross multiply
   1,109.50x = 1,528.46 × 777.30
4. Step 4: Simplify right side
   1,109.50x = 1,188,071.96
5. Step 5: Solve for x
   x = 1,188,071.96/1,109.50
6. Step 6: Final answer
   x = 1,070.82