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Finding the Fourth Proportional to 142.78, 215.14 and 117.66

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Solution

The fourth proportional to 142.78, 215.14 and 117.66 is: 177.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    142.78 : 215.14 = 117.66 : x
  2. Step 2: Convert to fraction form
    142.78/215.14 = 117.66/x
  3. Step 3: Cross multiply
    142.78x = 215.14 × 117.66
  4. Step 4: Simplify right side
    142.78x = 25,313.37
  5. Step 5: Solve for x
    x = 25,313.37/142.78
  6. Step 6: Final answer
    x = 177.29

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.