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Finding the Fourth Proportional to 648.21, 971.76 and 257.96

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Solution

The fourth proportional to 648.21, 971.76 and 257.96 is: 386.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    648.21 : 971.76 = 257.96 : x
  2. Step 2: Convert to fraction form
    648.21/971.76 = 257.96/x
  3. Step 3: Cross multiply
    648.21x = 971.76 × 257.96
  4. Step 4: Simplify right side
    648.21x = 250,675.21
  5. Step 5: Solve for x
    x = 250,675.21/648.21
  6. Step 6: Final answer
    x = 386.72

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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.