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Finding the Fourth Proportional to 76.18, 105.09 and 45.09

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Solution

The fourth proportional to 76.18, 105.09 and 45.09 is: 62.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.18 : 105.09 = 45.09 : x
  2. Step 2: Convert to fraction form
    76.18/105.09 = 45.09/x
  3. Step 3: Cross multiply
    76.18x = 105.09 × 45.09
  4. Step 4: Simplify right side
    76.18x = 4,738.73
  5. Step 5: Solve for x
    x = 4,738.73/76.18
  6. Step 6: Final answer
    x = 62.20

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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.