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Finding the Fourth Proportional to 76.08, 105.12 and 63.12

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Solution

The fourth proportional to 76.08, 105.12 and 63.12 is: 87.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.08 : 105.12 = 63.12 : x
  2. Step 2: Convert to fraction form
    76.08/105.12 = 63.12/x
  3. Step 3: Cross multiply
    76.08x = 105.12 × 63.12
  4. Step 4: Simplify right side
    76.08x = 6,635.17
  5. Step 5: Solve for x
    x = 6,635.17/76.08
  6. Step 6: Final answer
    x = 87.21

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.