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Finding the Fourth Proportional to 84.20, 116.15 and 56.61

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Solution

The fourth proportional to 84.20, 116.15 and 56.61 is: 78.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.20 : 116.15 = 56.61 : x
  2. Step 2: Convert to fraction form
    84.20/116.15 = 56.61/x
  3. Step 3: Cross multiply
    84.20x = 116.15 × 56.61
  4. Step 4: Simplify right side
    84.20x = 6,574.97
  5. Step 5: Solve for x
    x = 6,574.97/84.20
  6. Step 6: Final answer
    x = 78.09

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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.