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Finding the Fourth Proportional to 71.55, 107.12 and 66.69

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Solution

The fourth proportional to 71.55, 107.12 and 66.69 is: 99.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.55 : 107.12 = 66.69 : x
  2. Step 2: Convert to fraction form
    71.55/107.12 = 66.69/x
  3. Step 3: Cross multiply
    71.55x = 107.12 × 66.69
  4. Step 4: Simplify right side
    71.55x = 7,144.00
  5. Step 5: Solve for x
    x = 7,144.00/71.55
  6. Step 6: Final answer
    x = 99.85

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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.