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Finding the Fourth Proportional to 142.21, 213.52 and 81.46

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Solution

The fourth proportional to 142.21, 213.52 and 81.46 is: 122.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    142.21 : 213.52 = 81.46 : x
  2. Step 2: Convert to fraction form
    142.21/213.52 = 81.46/x
  3. Step 3: Cross multiply
    142.21x = 213.52 × 81.46
  4. Step 4: Simplify right side
    142.21x = 17,393.34
  5. Step 5: Solve for x
    x = 17,393.34/142.21
  6. Step 6: Final answer
    x = 122.31

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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.