Finding the Fourth Proportional to 860.31, 1,290.53 and 758.31

Step by Step Solution

1. Step 1: Write the proportion equation
   860.31 : 1,290.53 = 758.31 : x
2. Step 2: Convert to fraction form
   860.31/1,290.53 = 758.31/x
3. Step 3: Cross multiply
   860.31x = 1,290.53 × 758.31
4. Step 4: Simplify right side
   860.31x = 978,618.01
5. Step 5: Solve for x
   x = 978,618.01/860.31
6. Step 6: Final answer
   x = 1,137.52