Finding the Fourth Proportional to 1,438.17, 1,984.64 and 808.70

Step by Step Solution

1. Step 1: Write the proportion equation
   1,438.17 : 1,984.64 = 808.70 : x
2. Step 2: Convert to fraction form
   1,438.17/1,984.64 = 808.70/x
3. Step 3: Cross multiply
   1,438.17x = 1,984.64 × 808.70
4. Step 4: Simplify right side
   1,438.17x = 1,604,978.37
5. Step 5: Solve for x
   x = 1,604,978.37/1,438.17
6. Step 6: Final answer
   x = 1,115.99