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Finding the Fourth Proportional to 142.82, 212.64 and 140.80

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Solution

The fourth proportional to 142.82, 212.64 and 140.80 is: 209.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    142.82 : 212.64 = 140.80 : x
  2. Step 2: Convert to fraction form
    142.82/212.64 = 140.80/x
  3. Step 3: Cross multiply
    142.82x = 212.64 × 140.80
  4. Step 4: Simplify right side
    142.82x = 29,939.71
  5. Step 5: Solve for x
    x = 29,939.71/142.82
  6. Step 6: Final answer
    x = 209.63

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.