Finding the Fourth Proportional to 820.61, 1,131.52 and 670.76

Step by Step Solution

1. Step 1: Write the proportion equation
   820.61 : 1,131.52 = 670.76 : x
2. Step 2: Convert to fraction form
   820.61/1,131.52 = 670.76/x
3. Step 3: Cross multiply
   820.61x = 1,131.52 × 670.76
4. Step 4: Simplify right side
   820.61x = 758,978.25
5. Step 5: Solve for x
   x = 758,978.25/820.61
6. Step 6: Final answer
   x = 924.90