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Finding the Fourth Proportional to 77.62, 115.74 and 72.76

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Solution

The fourth proportional to 77.62, 115.74 and 72.76 is: 108.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.62 : 115.74 = 72.76 : x
  2. Step 2: Convert to fraction form
    77.62/115.74 = 72.76/x
  3. Step 3: Cross multiply
    77.62x = 115.74 × 72.76
  4. Step 4: Simplify right side
    77.62x = 8,421.24
  5. Step 5: Solve for x
    x = 8,421.24/77.62
  6. Step 6: Final answer
    x = 108.49

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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.