Finding the Fourth Proportional to 1,113.48, 1,536.82 and 641.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,113.48 : 1,536.82 = 641.69 : x
2. Step 2: Convert to fraction form
   1,113.48/1,536.82 = 641.69/x
3. Step 3: Cross multiply
   1,113.48x = 1,536.82 × 641.69
4. Step 4: Simplify right side
   1,113.48x = 986,158.82
5. Step 5: Solve for x
   x = 986,158.82/1,113.48
6. Step 6: Final answer
   x = 885.65