Finding the Fourth Proportional to 1,009.02, 1,510.78 and 764.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,009.02 : 1,510.78 = 764.80 : x
2. Step 2: Convert to fraction form
   1,009.02/1,510.78 = 764.80/x
3. Step 3: Cross multiply
   1,009.02x = 1,510.78 × 764.80
4. Step 4: Simplify right side
   1,009.02x = 1,155,444.54
5. Step 5: Solve for x
   x = 1,155,444.54/1,009.02
6. Step 6: Final answer
   x = 1,145.12