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Finding the Fourth Proportional to 138.52, 207.80 and 84.76

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Solution

The fourth proportional to 138.52, 207.80 and 84.76 is: 127.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    138.52 : 207.80 = 84.76 : x
  2. Step 2: Convert to fraction form
    138.52/207.80 = 84.76/x
  3. Step 3: Cross multiply
    138.52x = 207.80 × 84.76
  4. Step 4: Simplify right side
    138.52x = 17,613.13
  5. Step 5: Solve for x
    x = 17,613.13/138.52
  6. Step 6: Final answer
    x = 127.15

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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.