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Finding the Fourth Proportional to 76.40, 105.45 and 55.73

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Solution

The fourth proportional to 76.40, 105.45 and 55.73 is: 76.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    76.40 : 105.45 = 55.73 : x
  2. Step 2: Convert to fraction form
    76.40/105.45 = 55.73/x
  3. Step 3: Cross multiply
    76.40x = 105.45 × 55.73
  4. Step 4: Simplify right side
    76.40x = 5,876.73
  5. Step 5: Solve for x
    x = 5,876.73/76.40
  6. Step 6: Final answer
    x = 76.92

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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.