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Finding the Fourth Proportional to 137.52, 189.76 and 79.28

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Solution

The fourth proportional to 137.52, 189.76 and 79.28 is: 109.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    137.52 : 189.76 = 79.28 : x
  2. Step 2: Convert to fraction form
    137.52/189.76 = 79.28/x
  3. Step 3: Cross multiply
    137.52x = 189.76 × 79.28
  4. Step 4: Simplify right side
    137.52x = 15,044.17
  5. Step 5: Solve for x
    x = 15,044.17/137.52
  6. Step 6: Final answer
    x = 109.40

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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.