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Finding the Fourth Proportional to 55.20, 76.01 and 47.78

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Solution

The fourth proportional to 55.20, 76.01 and 47.78 is: 65.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    55.20 : 76.01 = 47.78 : x
  2. Step 2: Convert to fraction form
    55.20/76.01 = 47.78/x
  3. Step 3: Cross multiply
    55.20x = 76.01 × 47.78
  4. Step 4: Simplify right side
    55.20x = 3,631.14
  5. Step 5: Solve for x
    x = 3,631.14/55.20
  6. Step 6: Final answer
    x = 65.78

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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.