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Finding the Fourth Proportional to 142.78, 213.76 and 140.76

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Solution

The fourth proportional to 142.78, 213.76 and 140.76 is: 210.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    142.78 : 213.76 = 140.76 : x
  2. Step 2: Convert to fraction form
    142.78/213.76 = 140.76/x
  3. Step 3: Cross multiply
    142.78x = 213.76 × 140.76
  4. Step 4: Simplify right side
    142.78x = 30,088.86
  5. Step 5: Solve for x
    x = 30,088.86/142.78
  6. Step 6: Final answer
    x = 210.74

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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.