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Finding the Fourth Proportional to 72.31, 107.87 and 65.81

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Solution

The fourth proportional to 72.31, 107.87 and 65.81 is: 98.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.31 : 107.87 = 65.81 : x
  2. Step 2: Convert to fraction form
    72.31/107.87 = 65.81/x
  3. Step 3: Cross multiply
    72.31x = 107.87 × 65.81
  4. Step 4: Simplify right side
    72.31x = 7,098.92
  5. Step 5: Solve for x
    x = 7,098.92/72.31
  6. Step 6: Final answer
    x = 98.18

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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.