Finding the Fourth Proportional to 1,388.69, 1,917.96 and 945.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,388.69 : 1,917.96 = 945.82 : x
2. Step 2: Convert to fraction form
   1,388.69/1,917.96 = 945.82/x
3. Step 3: Cross multiply
   1,388.69x = 1,917.96 × 945.82
4. Step 4: Simplify right side
   1,388.69x = 1,814,040.13
5. Step 5: Solve for x
   x = 1,814,040.13/1,388.69
6. Step 6: Final answer
   x = 1,306.30