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Finding the Fourth Proportional to 648.20, 971.90 and 258.26

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Solution

The fourth proportional to 648.20, 971.90 and 258.26 is: 387.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    648.20 : 971.90 = 258.26 : x
  2. Step 2: Convert to fraction form
    648.20/971.90 = 258.26/x
  3. Step 3: Cross multiply
    648.20x = 971.90 × 258.26
  4. Step 4: Simplify right side
    648.20x = 251,000.50
  5. Step 5: Solve for x
    x = 251,000.50/648.20
  6. Step 6: Final answer
    x = 387.23

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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.