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Finding the Fourth Proportional to 66.98, 100.39 and 39.87

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Solution

The fourth proportional to 66.98, 100.39 and 39.87 is: 59.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    66.98 : 100.39 = 39.87 : x
  2. Step 2: Convert to fraction form
    66.98/100.39 = 39.87/x
  3. Step 3: Cross multiply
    66.98x = 100.39 × 39.87
  4. Step 4: Simplify right side
    66.98x = 4,002.24
  5. Step 5: Solve for x
    x = 4,002.24/66.98
  6. Step 6: Final answer
    x = 59.76

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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.