Finding the Fourth Proportional to 1,535.86, 2,117.25 and 1,221.25

Step by Step Solution

1. Step 1: Write the proportion equation
   1,535.86 : 2,117.25 = 1,221.25 : x
2. Step 2: Convert to fraction form
   1,535.86/2,117.25 = 1,221.25/x
3. Step 3: Cross multiply
   1,535.86x = 2,117.25 × 1,221.25
4. Step 4: Simplify right side
   1,535.86x = 2,585,683.83
5. Step 5: Solve for x
   x = 2,585,683.83/1,535.86
6. Step 6: Final answer
   x = 1,683.54