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Finding the Fourth Proportional to 621.15, 857.43 and 555.54

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Solution

The fourth proportional to 621.15, 857.43 and 555.54 is: 766.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.15 : 857.43 = 555.54 : x
  2. Step 2: Convert to fraction form
    621.15/857.43 = 555.54/x
  3. Step 3: Cross multiply
    621.15x = 857.43 × 555.54
  4. Step 4: Simplify right side
    621.15x = 476,336.66
  5. Step 5: Solve for x
    x = 476,336.66/621.15
  6. Step 6: Final answer
    x = 766.86

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.