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Finding the Fourth Proportional to 55.21, 82.40 and 54.31

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Solution

The fourth proportional to 55.21, 82.40 and 54.31 is: 81.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    55.21 : 82.40 = 54.31 : x
  2. Step 2: Convert to fraction form
    55.21/82.40 = 54.31/x
  3. Step 3: Cross multiply
    55.21x = 82.40 × 54.31
  4. Step 4: Simplify right side
    55.21x = 4,475.14
  5. Step 5: Solve for x
    x = 4,475.14/55.21
  6. Step 6: Final answer
    x = 81.06

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.