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Finding the Fourth Proportional to 63.90, 87.72 and 61.44

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Solution

The fourth proportional to 63.90, 87.72 and 61.44 is: 84.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    63.90 : 87.72 = 61.44 : x
  2. Step 2: Convert to fraction form
    63.90/87.72 = 61.44/x
  3. Step 3: Cross multiply
    63.90x = 87.72 × 61.44
  4. Step 4: Simplify right side
    63.90x = 5,389.52
  5. Step 5: Solve for x
    x = 5,389.52/63.90
  6. Step 6: Final answer
    x = 84.34

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.