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Finding the Fourth Proportional to 55.38, 76.47 and 39.89

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Solution

The fourth proportional to 55.38, 76.47 and 39.89 is: 55.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    55.38 : 76.47 = 39.89 : x
  2. Step 2: Convert to fraction form
    55.38/76.47 = 39.89/x
  3. Step 3: Cross multiply
    55.38x = 76.47 × 39.89
  4. Step 4: Simplify right side
    55.38x = 3,050.01
  5. Step 5: Solve for x
    x = 3,050.01/55.38
  6. Step 6: Final answer
    x = 55.07

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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.