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Finding the Fourth Proportional to 76.76, 115.20 and 70.64

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Solution

The fourth proportional to 76.76, 115.20 and 70.64 is: 106.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.76 : 115.20 = 70.64 : x
  2. Step 2: Convert to fraction form
    76.76/115.20 = 70.64/x
  3. Step 3: Cross multiply
    76.76x = 115.20 × 70.64
  4. Step 4: Simplify right side
    76.76x = 8,137.73
  5. Step 5: Solve for x
    x = 8,137.73/76.76
  6. Step 6: Final answer
    x = 106.02

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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.