Finding the Fourth Proportional to 1,287.30, 1,926.16 and 767.59

Step by Step Solution

1. Step 1: Write the proportion equation
   1,287.30 : 1,926.16 = 767.59 : x
2. Step 2: Convert to fraction form
   1,287.30/1,926.16 = 767.59/x
3. Step 3: Cross multiply
   1,287.30x = 1,926.16 × 767.59
4. Step 4: Simplify right side
   1,287.30x = 1,478,501.15
5. Step 5: Solve for x
   x = 1,478,501.15/1,287.30
6. Step 6: Final answer
   x = 1,148.53