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Finding the Fourth Proportional to 61.55, 84.89 and 57.20

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Solution

The fourth proportional to 61.55, 84.89 and 57.20 is: 78.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    61.55 : 84.89 = 57.20 : x
  2. Step 2: Convert to fraction form
    61.55/84.89 = 57.20/x
  3. Step 3: Cross multiply
    61.55x = 84.89 × 57.20
  4. Step 4: Simplify right side
    61.55x = 4,855.00
  5. Step 5: Solve for x
    x = 4,855.00/61.55
  6. Step 6: Final answer
    x = 78.89

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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.