Finding the Fourth Proportional to 1,391.16, 1,919.86 and 761.71

Step by Step Solution

1. Step 1: Write the proportion equation
   1,391.16 : 1,919.86 = 761.71 : x
2. Step 2: Convert to fraction form
   1,391.16/1,919.86 = 761.71/x
3. Step 3: Cross multiply
   1,391.16x = 1,919.86 × 761.71
4. Step 4: Simplify right side
   1,391.16x = 1,462,376.56
5. Step 5: Solve for x
   x = 1,462,376.56/1,391.16
6. Step 6: Final answer
   x = 1,051.19