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Finding the Fourth Proportional to 55.66, 76.81 and 31.09

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Solution

The fourth proportional to 55.66, 76.81 and 31.09 is: 42.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    55.66 : 76.81 = 31.09 : x
  2. Step 2: Convert to fraction form
    55.66/76.81 = 31.09/x
  3. Step 3: Cross multiply
    55.66x = 76.81 × 31.09
  4. Step 4: Simplify right side
    55.66x = 2,388.02
  5. Step 5: Solve for x
    x = 2,388.02/55.66
  6. Step 6: Final answer
    x = 42.90

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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.