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Finding the Fourth Proportional to 63.85, 87.90 and 55.66

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Solution

The fourth proportional to 63.85, 87.90 and 55.66 is: 76.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    63.85 : 87.90 = 55.66 : x
  2. Step 2: Convert to fraction form
    63.85/87.90 = 55.66/x
  3. Step 3: Cross multiply
    63.85x = 87.90 × 55.66
  4. Step 4: Simplify right side
    63.85x = 4,892.51
  5. Step 5: Solve for x
    x = 4,892.51/63.85
  6. Step 6: Final answer
    x = 76.63

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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.