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Finding the Fourth Proportional to 63.21, 87.30 and 55.11

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Solution

The fourth proportional to 63.21, 87.30 and 55.11 is: 76.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    63.21 : 87.30 = 55.11 : x
  2. Step 2: Convert to fraction form
    63.21/87.30 = 55.11/x
  3. Step 3: Cross multiply
    63.21x = 87.30 × 55.11
  4. Step 4: Simplify right side
    63.21x = 4,811.10
  5. Step 5: Solve for x
    x = 4,811.10/63.21
  6. Step 6: Final answer
    x = 76.11

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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.