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Finding the Fourth Proportional to 55.05, 82.57 and 20.80

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Solution

The fourth proportional to 55.05, 82.57 and 20.80 is: 31.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    55.05 : 82.57 = 20.80 : x
  2. Step 2: Convert to fraction form
    55.05/82.57 = 20.80/x
  3. Step 3: Cross multiply
    55.05x = 82.57 × 20.80
  4. Step 4: Simplify right side
    55.05x = 1,717.46
  5. Step 5: Solve for x
    x = 1,717.46/55.05
  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.