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Finding the Fourth Proportional to 61.11, 84.28 and 39.30

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Solution

The fourth proportional to 61.11, 84.28 and 39.30 is: 54.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    61.11 : 84.28 = 39.30 : x
  2. Step 2: Convert to fraction form
    61.11/84.28 = 39.30/x
  3. Step 3: Cross multiply
    61.11x = 84.28 × 39.30
  4. Step 4: Simplify right side
    61.11x = 3,312.20
  5. Step 5: Solve for x
    x = 3,312.20/61.11
  6. Step 6: Final answer
    x = 54.20

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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.