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Finding the Fourth Proportional to 76.76, 115.34 and 71.90

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Solution

The fourth proportional to 76.76, 115.34 and 71.90 is: 108.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.76 : 115.34 = 71.90 : x
  2. Step 2: Convert to fraction form
    76.76/115.34 = 71.90/x
  3. Step 3: Cross multiply
    76.76x = 115.34 × 71.90
  4. Step 4: Simplify right side
    76.76x = 8,292.95
  5. Step 5: Solve for x
    x = 8,292.95/76.76
  6. Step 6: Final answer
    x = 108.04

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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.