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Finding the Fourth Proportional to 126.39, 189.54 and 72.30

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Solution

The fourth proportional to 126.39, 189.54 and 72.30 is: 108.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    126.39 : 189.54 = 72.30 : x
  2. Step 2: Convert to fraction form
    126.39/189.54 = 72.30/x
  3. Step 3: Cross multiply
    126.39x = 189.54 × 72.30
  4. Step 4: Simplify right side
    126.39x = 13,703.74
  5. Step 5: Solve for x
    x = 13,703.74/126.39
  6. Step 6: Final answer
    x = 108.42

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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.