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Finding the Fourth Proportional to 103.62, 142.89 and 66.72

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Solution

The fourth proportional to 103.62, 142.89 and 66.72 is: 92.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.62 : 142.89 = 66.72 : x
  2. Step 2: Convert to fraction form
    103.62/142.89 = 66.72/x
  3. Step 3: Cross multiply
    103.62x = 142.89 × 66.72
  4. Step 4: Simplify right side
    103.62x = 9,533.62
  5. Step 5: Solve for x
    x = 9,533.62/103.62
  6. Step 6: Final answer
    x = 92.01

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.