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Finding the Fourth Proportional to 84.72, 127.08 and 42

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Solution

The fourth proportional to 84.72, 127.08 and 42 is: 63

Step by Step Solution

  1. Step 1: Write the proportion equation
    84.72 : 127.08 = 42 : x
  2. Step 2: Convert to fraction form
    84.72/127.08 = 42/x
  3. Step 3: Cross multiply
    84.72x = 127.08 × 42
  4. Step 4: Simplify right side
    84.72x = 5,337.36
  5. Step 5: Solve for x
    x = 5,337.36/84.72
  6. Step 6: Final answer
    x = 63

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.