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Finding the Fourth Proportional to 61.21, 84.45 and 39.07

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Solution

The fourth proportional to 61.21, 84.45 and 39.07 is: 53.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    61.21 : 84.45 = 39.07 : x
  2. Step 2: Convert to fraction form
    61.21/84.45 = 39.07/x
  3. Step 3: Cross multiply
    61.21x = 84.45 × 39.07
  4. Step 4: Simplify right side
    61.21x = 3,299.46
  5. Step 5: Solve for x
    x = 3,299.46/61.21
  6. Step 6: Final answer
    x = 53.90

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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.