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Finding the Fourth Proportional to 258.02, 387.45 and 217.70

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Solution

The fourth proportional to 258.02, 387.45 and 217.70 is: 326.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.02 : 387.45 = 217.70 : x
  2. Step 2: Convert to fraction form
    258.02/387.45 = 217.70/x
  3. Step 3: Cross multiply
    258.02x = 387.45 × 217.70
  4. Step 4: Simplify right side
    258.02x = 84,347.87
  5. Step 5: Solve for x
    x = 84,347.87/258.02
  6. Step 6: Final answer
    x = 326.90

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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.