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Finding the Fourth Proportional to 616.80, 851.04 and 420.72

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Solution

The fourth proportional to 616.80, 851.04 and 420.72 is: 580.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    616.80 : 851.04 = 420.72 : x
  2. Step 2: Convert to fraction form
    616.80/851.04 = 420.72/x
  3. Step 3: Cross multiply
    616.80x = 851.04 × 420.72
  4. Step 4: Simplify right side
    616.80x = 358,049.55
  5. Step 5: Solve for x
    x = 358,049.55/616.80
  6. Step 6: Final answer
    x = 580.50

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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.