Finding the Fourth Proportional to 1,385.69, 2,077.85 and 947.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,385.69 : 2,077.85 = 947.61 : x
2. Step 2: Convert to fraction form
   1,385.69/2,077.85 = 947.61/x
3. Step 3: Cross multiply
   1,385.69x = 2,077.85 × 947.61
4. Step 4: Simplify right side
   1,385.69x = 1,968,993.81
5. Step 5: Solve for x
   x = 1,968,993.81/1,385.69
6. Step 6: Final answer
   x = 1,420.95