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Finding the Fourth Proportional to 61.75, 85.17 and 39.63

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Solution

The fourth proportional to 61.75, 85.17 and 39.63 is: 54.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    61.75 : 85.17 = 39.63 : x
  2. Step 2: Convert to fraction form
    61.75/85.17 = 39.63/x
  3. Step 3: Cross multiply
    61.75x = 85.17 × 39.63
  4. Step 4: Simplify right side
    61.75x = 3,375.29
  5. Step 5: Solve for x
    x = 3,375.29/61.75
  6. Step 6: Final answer
    x = 54.66

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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.