Finding the Fourth Proportional to 1,407.21, 1,942.25 and 817.71

Step by Step Solution

1. Step 1: Write the proportion equation
   1,407.21 : 1,942.25 = 817.71 : x
2. Step 2: Convert to fraction form
   1,407.21/1,942.25 = 817.71/x
3. Step 3: Cross multiply
   1,407.21x = 1,942.25 × 817.71
4. Step 4: Simplify right side
   1,407.21x = 1,588,193.16
5. Step 5: Solve for x
   x = 1,588,193.16/1,407.21
6. Step 6: Final answer
   x = 1,128.61