Finding the Fourth Proportional to 1,353.60, 1,868.82 and 1,213.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,353.60 : 1,868.82 = 1,213.50 : x
2. Step 2: Convert to fraction form
   1,353.60/1,868.82 = 1,213.50/x
3. Step 3: Cross multiply
   1,353.60x = 1,868.82 × 1,213.50
4. Step 4: Simplify right side
   1,353.60x = 2,267,813.07
5. Step 5: Solve for x
   x = 2,267,813.07/1,353.60
6. Step 6: Final answer
   x = 1,675.39