Finding the Fourth Proportional to 1,071.30, 1,607.40 and 765.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,071.30 : 1,607.40 = 765.12 : x
2. Step 2: Convert to fraction form
   1,071.30/1,607.40 = 765.12/x
3. Step 3: Cross multiply
   1,071.30x = 1,607.40 × 765.12
4. Step 4: Simplify right side
   1,071.30x = 1,229,853.89
5. Step 5: Solve for x
   x = 1,229,853.89/1,071.30
6. Step 6: Final answer
   x = 1,148.00