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Finding the Fourth Proportional to 76.98, 106.28 and 63.20

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Solution

The fourth proportional to 76.98, 106.28 and 63.20 is: 87.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.98 : 106.28 = 63.20 : x
  2. Step 2: Convert to fraction form
    76.98/106.28 = 63.20/x
  3. Step 3: Cross multiply
    76.98x = 106.28 × 63.20
  4. Step 4: Simplify right side
    76.98x = 6,716.05
  5. Step 5: Solve for x
    x = 6,716.05/76.98
  6. Step 6: Final answer
    x = 87.24

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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.