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Finding the Fourth Proportional to 680.87, 939.35 and 415.20

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Solution

The fourth proportional to 680.87, 939.35 and 415.20 is: 572.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.87 : 939.35 = 415.20 : x
  2. Step 2: Convert to fraction form
    680.87/939.35 = 415.20/x
  3. Step 3: Cross multiply
    680.87x = 939.35 × 415.20
  4. Step 4: Simplify right side
    680.87x = 390,016.04
  5. Step 5: Solve for x
    x = 390,016.04/680.87
  6. Step 6: Final answer
    x = 572.82

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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.