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Finding the Fourth Proportional to 142.20, 213.12 and 70.20

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Solution

The fourth proportional to 142.20, 213.12 and 70.20 is: 105.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    142.20 : 213.12 = 70.20 : x
  2. Step 2: Convert to fraction form
    142.20/213.12 = 70.20/x
  3. Step 3: Cross multiply
    142.20x = 213.12 × 70.20
  4. Step 4: Simplify right side
    142.20x = 14,961.02
  5. Step 5: Solve for x
    x = 14,961.02/142.20
  6. Step 6: Final answer
    x = 105.21

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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.