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Finding the Fourth Proportional to 71.78, 107.21 and 62.18

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Solution

The fourth proportional to 71.78, 107.21 and 62.18 is: 92.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.78 : 107.21 = 62.18 : x
  2. Step 2: Convert to fraction form
    71.78/107.21 = 62.18/x
  3. Step 3: Cross multiply
    71.78x = 107.21 × 62.18
  4. Step 4: Simplify right side
    71.78x = 6,665.47
  5. Step 5: Solve for x
    x = 6,665.47/71.78
  6. Step 6: Final answer
    x = 92.87

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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.