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Finding the Fourth Proportional to 71.47, 107.21 and 30.92

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Solution

The fourth proportional to 71.47, 107.21 and 30.92 is: 46.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.47 : 107.21 = 30.92 : x
  2. Step 2: Convert to fraction form
    71.47/107.21 = 30.92/x
  3. Step 3: Cross multiply
    71.47x = 107.21 × 30.92
  4. Step 4: Simplify right side
    71.47x = 3,314.93
  5. Step 5: Solve for x
    x = 3,314.93/71.47
  6. Step 6: Final answer
    x = 46.38

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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.