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Finding the Fourth Proportional to 258.67, 388.17 and 143.20

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Solution

The fourth proportional to 258.67, 388.17 and 143.20 is: 214.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.67 : 388.17 = 143.20 : x
  2. Step 2: Convert to fraction form
    258.67/388.17 = 143.20/x
  3. Step 3: Cross multiply
    258.67x = 388.17 × 143.20
  4. Step 4: Simplify right side
    258.67x = 55,585.94
  5. Step 5: Solve for x
    x = 55,585.94/258.67
  6. Step 6: Final answer
    x = 214.89

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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.