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Finding the Fourth Proportional to 55.21, 82.80 and 20.95

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Solution

The fourth proportional to 55.21, 82.80 and 20.95 is: 31.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    55.21 : 82.80 = 20.95 : x
  2. Step 2: Convert to fraction form
    55.21/82.80 = 20.95/x
  3. Step 3: Cross multiply
    55.21x = 82.80 × 20.95
  4. Step 4: Simplify right side
    55.21x = 1,734.66
  5. Step 5: Solve for x
    x = 1,734.66/55.21
  6. Step 6: Final answer
    x = 31.42

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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.