Finding the Fourth Proportional to 1,645.88, 2,271.31 and 947.25

Step by Step Solution

1. Step 1: Write the proportion equation
   1,645.88 : 2,271.31 = 947.25 : x
2. Step 2: Convert to fraction form
   1,645.88/2,271.31 = 947.25/x
3. Step 3: Cross multiply
   1,645.88x = 2,271.31 × 947.25
4. Step 4: Simplify right side
   1,645.88x = 2,151,498.40
5. Step 5: Solve for x
   x = 2,151,498.40/1,645.88
6. Step 6: Final answer
   x = 1,307.20