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Finding the Fourth Proportional to 142.71, 214.28 and 81.96

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Solution

The fourth proportional to 142.71, 214.28 and 81.96 is: 123.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    142.71 : 214.28 = 81.96 : x
  2. Step 2: Convert to fraction form
    142.71/214.28 = 81.96/x
  3. Step 3: Cross multiply
    142.71x = 214.28 × 81.96
  4. Step 4: Simplify right side
    142.71x = 17,561.98
  5. Step 5: Solve for x
    x = 17,561.98/142.71
  6. Step 6: Final answer
    x = 123.06

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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.