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Finding the Fourth Proportional to 61.86, 85.26 and 55.71

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Solution

The fourth proportional to 61.86, 85.26 and 55.71 is: 76.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    61.86 : 85.26 = 55.71 : x
  2. Step 2: Convert to fraction form
    61.86/85.26 = 55.71/x
  3. Step 3: Cross multiply
    61.86x = 85.26 × 55.71
  4. Step 4: Simplify right side
    61.86x = 4,749.83
  5. Step 5: Solve for x
    x = 4,749.83/61.86
  6. Step 6: Final answer
    x = 76.78

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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.