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Finding the Fourth Proportional to 72.21, 108.34 and 55.13

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Solution

The fourth proportional to 72.21, 108.34 and 55.13 is: 82.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.21 : 108.34 = 55.13 : x
  2. Step 2: Convert to fraction form
    72.21/108.34 = 55.13/x
  3. Step 3: Cross multiply
    72.21x = 108.34 × 55.13
  4. Step 4: Simplify right side
    72.21x = 5,972.71
  5. Step 5: Solve for x
    x = 5,972.71/72.21
  6. Step 6: Final answer
    x = 82.72

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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.