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Finding the Fourth Proportional to 71.66, 107.31 and 65.90

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Solution

The fourth proportional to 71.66, 107.31 and 65.90 is: 98.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.66 : 107.31 = 65.90 : x
  2. Step 2: Convert to fraction form
    71.66/107.31 = 65.90/x
  3. Step 3: Cross multiply
    71.66x = 107.31 × 65.90
  4. Step 4: Simplify right side
    71.66x = 7,071.73
  5. Step 5: Solve for x
    x = 7,071.73/71.66
  6. Step 6: Final answer
    x = 98.68

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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.