Finding the Fourth Proportional to 1,211.30, 1,816.38 and 561.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,211.30 : 1,816.38 = 561.50 : x
2. Step 2: Convert to fraction form
   1,211.30/1,816.38 = 561.50/x
3. Step 3: Cross multiply
   1,211.30x = 1,816.38 × 561.50
4. Step 4: Simplify right side
   1,211.30x = 1,019,897.37
5. Step 5: Solve for x
   x = 1,019,897.37/1,211.30
6. Step 6: Final answer
   x = 841.99