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Finding the Fourth Proportional to 142.30, 212.87 and 105.71

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Solution

The fourth proportional to 142.30, 212.87 and 105.71 is: 158.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    142.30 : 212.87 = 105.71 : x
  2. Step 2: Convert to fraction form
    142.30/212.87 = 105.71/x
  3. Step 3: Cross multiply
    142.30x = 212.87 × 105.71
  4. Step 4: Simplify right side
    142.30x = 22,503.28
  5. Step 5: Solve for x
    x = 22,503.28/142.30
  6. Step 6: Final answer
    x = 158.14

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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.