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Finding the Fourth Proportional to 77.17, 115.10 and 72.88

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Solution

The fourth proportional to 77.17, 115.10 and 72.88 is: 108.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.17 : 115.10 = 72.88 : x
  2. Step 2: Convert to fraction form
    77.17/115.10 = 72.88/x
  3. Step 3: Cross multiply
    77.17x = 115.10 × 72.88
  4. Step 4: Simplify right side
    77.17x = 8,388.49
  5. Step 5: Solve for x
    x = 8,388.49/77.17
  6. Step 6: Final answer
    x = 108.70

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.