Finding the Fourth Proportional to 1,421.38, 1,965.61 and 1,356.11

Step by Step Solution

1. Step 1: Write the proportion equation
   1,421.38 : 1,965.61 = 1,356.11 : x
2. Step 2: Convert to fraction form
   1,421.38/1,965.61 = 1,356.11/x
3. Step 3: Cross multiply
   1,421.38x = 1,965.61 × 1,356.11
4. Step 4: Simplify right side
   1,421.38x = 2,665,583.38
5. Step 5: Solve for x
   x = 2,665,583.38/1,421.38
6. Step 6: Final answer
   x = 1,875.35