Finding the Fourth Proportional to 1,424.18, 2,135.59 and 807.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,424.18 : 2,135.59 = 807.72 : x
2. Step 2: Convert to fraction form
   1,424.18/2,135.59 = 807.72/x
3. Step 3: Cross multiply
   1,424.18x = 2,135.59 × 807.72
4. Step 4: Simplify right side
   1,424.18x = 1,724,954.72
5. Step 5: Solve for x
   x = 1,724,954.72/1,424.18
6. Step 6: Final answer
   x = 1,211.19