Finding the Fourth Proportional to 1,111.21, 1,533.49 and 613.87

Step by Step Solution

1. Step 1: Write the proportion equation
   1,111.21 : 1,533.49 = 613.87 : x
2. Step 2: Convert to fraction form
   1,111.21/1,533.49 = 613.87/x
3. Step 3: Cross multiply
   1,111.21x = 1,533.49 × 613.87
4. Step 4: Simplify right side
   1,111.21x = 941,363.51
5. Step 5: Solve for x
   x = 941,363.51/1,111.21
6. Step 6: Final answer
   x = 847.15