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Finding the Fourth Proportional to 187.38, 258.53 and 129.20

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Solution

The fourth proportional to 187.38, 258.53 and 129.20 is: 178.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    187.38 : 258.53 = 129.20 : x
  2. Step 2: Convert to fraction form
    187.38/258.53 = 129.20/x
  3. Step 3: Cross multiply
    187.38x = 258.53 × 129.20
  4. Step 4: Simplify right side
    187.38x = 33,400.14
  5. Step 5: Solve for x
    x = 33,400.14/187.38
  6. Step 6: Final answer
    x = 178.25

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.