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Finding the Fourth Proportional to 142.78, 213.80 and 84.94

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Solution

The fourth proportional to 142.78, 213.80 and 84.94 is: 127.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    142.78 : 213.80 = 84.94 : x
  2. Step 2: Convert to fraction form
    142.78/213.80 = 84.94/x
  3. Step 3: Cross multiply
    142.78x = 213.80 × 84.94
  4. Step 4: Simplify right side
    142.78x = 18,160.17
  5. Step 5: Solve for x
    x = 18,160.17/142.78
  6. Step 6: Final answer
    x = 127.19

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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.