Finding the Fourth Proportional to 1,390.19, 1,920.03 and 947.33

Step by Step Solution

1. Step 1: Write the proportion equation
   1,390.19 : 1,920.03 = 947.33 : x
2. Step 2: Convert to fraction form
   1,390.19/1,920.03 = 947.33/x
3. Step 3: Cross multiply
   1,390.19x = 1,920.03 × 947.33
4. Step 4: Simplify right side
   1,390.19x = 1,818,892.42
5. Step 5: Solve for x
   x = 1,818,892.42/1,390.19
6. Step 6: Final answer
   x = 1,308.38