Finding the Fourth Proportional to 1,390.82, 1,918.25 and 947.95

Step by Step Solution

1. Step 1: Write the proportion equation
   1,390.82 : 1,918.25 = 947.95 : x
2. Step 2: Convert to fraction form
   1,390.82/1,918.25 = 947.95/x
3. Step 3: Cross multiply
   1,390.82x = 1,918.25 × 947.95
4. Step 4: Simplify right side
   1,390.82x = 1,818,402.66
5. Step 5: Solve for x
   x = 1,818,402.66/1,390.82
6. Step 6: Final answer
   x = 1,307.44