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Finding the Fourth Proportional to 72.72, 109.11 and 31.57

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Solution

The fourth proportional to 72.72, 109.11 and 31.57 is: 47.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.72 : 109.11 = 31.57 : x
  2. Step 2: Convert to fraction form
    72.72/109.11 = 31.57/x
  3. Step 3: Cross multiply
    72.72x = 109.11 × 31.57
  4. Step 4: Simplify right side
    72.72x = 3,444.52
  5. Step 5: Solve for x
    x = 3,444.52/72.72
  6. Step 6: Final answer
    x = 47.37

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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.