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Finding the Fourth Proportional to 258.88, 388.32 and 145.12

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Solution

The fourth proportional to 258.88, 388.32 and 145.12 is: 217.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.88 : 388.32 = 145.12 : x
  2. Step 2: Convert to fraction form
    258.88/388.32 = 145.12/x
  3. Step 3: Cross multiply
    258.88x = 388.32 × 145.12
  4. Step 4: Simplify right side
    258.88x = 56,353.00
  5. Step 5: Solve for x
    x = 56,353.00/258.88
  6. Step 6: Final answer
    x = 217.68

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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.