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Finding the Fourth Proportional to 258.29, 387.42 and 87.29

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Solution

The fourth proportional to 258.29, 387.42 and 87.29 is: 130.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.29 : 387.42 = 87.29 : x
  2. Step 2: Convert to fraction form
    258.29/387.42 = 87.29/x
  3. Step 3: Cross multiply
    258.29x = 387.42 × 87.29
  4. Step 4: Simplify right side
    258.29x = 33,815.95
  5. Step 5: Solve for x
    x = 33,815.95/258.29
  6. Step 6: Final answer
    x = 130.92

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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.