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Finding the Fourth Proportional to 55.06, 82.57 and 20.81

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Solution

The fourth proportional to 55.06, 82.57 and 20.81 is: 31.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    55.06 : 82.57 = 20.81 : x
  2. Step 2: Convert to fraction form
    55.06/82.57 = 20.81/x
  3. Step 3: Cross multiply
    55.06x = 82.57 × 20.81
  4. Step 4: Simplify right side
    55.06x = 1,717.87
  5. Step 5: Solve for x
    x = 1,717.87/55.06
  6. Step 6: Final answer
    x = 31.20

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.